patchpretty-print: de-tabify indented logs to make things line up properly

diff --git a/pretty.c b/pretty.c
index 92b2870a7eab..0b40457f99f0 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1629,6 +1629,76 @@ void pp_title_line(struct pretty_print_context *pp,
 	strbuf_release(&title);
 }
 
+static int pp_utf8_width(const char *start, const char *end)
+{
+	int width = 0;
+	size_t remain = end - start;
+
+	while (remain) {
+		int n = utf8_width(&start, &remain);
+		if (n < 0 || !start)
+			return -1;
+		width += n;
+	}
+	return width;
+}
+
+/*
+ * pp_handle_indent() prints out the intendation, and
+ * perhaps the whole line (without the final newline)
+ *
+ * Why "perhaps"? If there are tabs in the indented line
+ * it will print it out in order to de-tabify the line.
+ *
+ * But if there are no tabs, we just fall back on the
+ * normal "print the whole line".
+ */
+static int pp_handle_indent(struct strbuf *sb, int indent,
+			     const char *line, int linelen)
+{
+	const char *tab;
+
+	strbuf_addchars(sb, ' ', indent);
+
+	tab = memchr(line, '\t', linelen);
+	if (!tab)
+		return 0;
+
+	do {
+		int width = pp_utf8_width(line, tab);
+
+		/*
+		 * If it wasn't well-formed utf8, or it
+		 * had characters with badly defined
+		 * width (control characters etc), just
+		 * give up on trying to align things.
+		 */
+		if (width < 0)
+			break;
+
+		/* Output the data .. */
+		strbuf_add(sb, line, tab - line);
+
+		/* .. and the de-tabified tab */
+		strbuf_addchars(sb, ' ', 8-(width & 7));
+
+		/* Skip over the printed part .. */
+		linelen -= 1+tab-line;
+		line = tab + 1;
+
+		/* .. and look for the next tab */
+		tab = memchr(line, '\t', linelen);
+	} while (tab);
+
+	/*
+	 * Print out everything after the last tab without
+	 * worrying about width - there's nothing more to
+	 * align.
+	 */
+	strbuf_add(sb, line, linelen);
+	return 1;
+}
+
 void pp_remainder(struct pretty_print_context *pp,
 		  const char **msg_p,
 		  struct strbuf *sb,
@@ -1652,8 +1722,10 @@ void pp_remainder(struct pretty_print_context *pp,
 		first = 0;
 
 		strbuf_grow(sb, linelen + indent + 20);
-		if (indent)
-			strbuf_addchars(sb, ' ', indent);
+		if (indent) {
+			if (pp_handle_indent(sb, indent, line, linelen))
+				linelen = 0;
+		}
 		strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
 	}

@@ -1723,10 +1711,14 @@ void pp_remainder(struct pretty_print_context *pp,
 
 		strbuf_grow(sb, linelen + indent + 20);
 		if (indent) {
-			if (pp_handle_indent(sb, indent, line, linelen))
-				linelen = 0;
+			strbuf_addchars(sb, ' ', indent);
+			if (pp->fmt == CMIT_FMT_EXPAND_TABS)
+				strbuf_expand_add(sb, line, linelen);
+			else
+				strbuf_add(sb, line, linelen);
+		} else {
+			strbuf_add(sb, line, linelen);
 		}
-		strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
 	}
 }

pretty.c, t/t4201-shortlog.sh

diff --git a/pretty.c b/pretty.c
index 92b2870..0b40457 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1629,6 +1629,76 @@ void pp_title_line(struct pretty_print_context *pp,
 	strbuf_release(&title);
 }
 
+static int pp_utf8_width(const char *start, const char *end)
+{
+	int width = 0;
+	size_t remain = end - start;
+
+	while (remain) {
+		int n = utf8_width(&start, &remain);
+		if (n < 0 || !start)
+			return -1;
+		width += n;
+	}
+	return width;
+}
+
+/*
+ * pp_handle_indent() prints out the intendation, and
+ * perhaps the whole line (without the final newline)
+ *
+ * Why "perhaps"? If there are tabs in the indented line
+ * it will print it out in order to de-tabify the line.
+ *
+ * But if there are no tabs, we just fall back on the
+ * normal "print the whole line".
+ */
+static int pp_handle_indent(struct strbuf *sb, int indent,
+			     const char *line, int linelen)
+{
+	const char *tab;
+
+	strbuf_addchars(sb, ' ', indent);
+
+	tab = memchr(line, '\t', linelen);
+	if (!tab)
+		return 0;
+
+	do {
+		int width = pp_utf8_width(line, tab);
+
+		/*
+		 * If it wasn't well-formed utf8, or it
+		 * had characters with badly defined
+		 * width (control characters etc), just
+		 * give up on trying to align things.
+		 */
+		if (width < 0)
+			break;
+
+		/* Output the data .. */
+		strbuf_add(sb, line, tab - line);
+
+		/* .. and the de-tabified tab */
+		strbuf_addchars(sb, ' ', 8-(width & 7));
+
+		/* Skip over the printed part .. */
+		linelen -= 1+tab-line;
+		line = tab + 1;
+
+		/* .. and look for the next tab */
+		tab = memchr(line, '\t', linelen);
+	} while (tab);
+
+	/*
+	 * Print out everything after the last tab without
+	 * worrying about width - there's nothing more to
+	 * align.
+	 */
+	strbuf_add(sb, line, linelen);
+	return 1;
+}
+
 void pp_remainder(struct pretty_print_context *pp,
 		  const char **msg_p,
 		  struct strbuf *sb,
@@ -1652,8 +1722,10 @@ void pp_remainder(struct pretty_print_context *pp,
 		first = 0;
 
 		strbuf_grow(sb, linelen + indent + 20);
-		if (indent)
-			strbuf_addchars(sb, ' ', indent);
+		if (indent) {
+			if (pp_handle_indent(sb, indent, line, linelen))
+				linelen = 0;
+		}
 		strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
 	}
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 7600a3e..987b708 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -93,7 +93,7 @@ test_expect_success 'output from user-defined format is re-wrapped' '
 	test_cmp expect log.predictable
 '
 
-test_expect_success !MINGW 'shortlog wrapping' '
+test_expect_failure !MINGW 'shortlog wrapping' '
 	cat >expect <<\EOF &&
 A U Thor (5):
       Test
@@ -114,7 +114,7 @@ EOF
 	test_cmp expect out
 '
 
-test_expect_success !MINGW 'shortlog from non-git directory' '
+test_expect_failure !MINGW 'shortlog from non-git directory' '
 	git log HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out

diff --git a/pretty.c b/pretty.c
index 0b40457..6d657fc 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1645,26 +1645,17 @@ static int pp_utf8_width(const char *start, const char *end)
 
 /*
  * pp_handle_indent() prints out the intendation, and
- * perhaps the whole line (without the final newline)
- *
- * Why "perhaps"? If there are tabs in the indented line
- * it will print it out in order to de-tabify the line.
- *
- * But if there are no tabs, we just fall back on the
- * normal "print the whole line".
+ * the whole line (without the final newline), after
+ * de-tabifying.
  */
-static int pp_handle_indent(struct strbuf *sb, int indent,
+static void pp_handle_indent(struct strbuf *sb, int indent,
 			     const char *line, int linelen)
 {
 	const char *tab;
 
 	strbuf_addchars(sb, ' ', indent);
 
-	tab = memchr(line, '\t', linelen);
-	if (!tab)
-		return 0;
-
-	do {
+	while ((tab = memchr(line, '\t', linelen)) != NULL) {
 		int width = pp_utf8_width(line, tab);
 
 		/*
@@ -1685,10 +1676,7 @@ static int pp_handle_indent(struct strbuf *sb, int indent,
 		/* Skip over the printed part .. */
 		linelen -= 1+tab-line;
 		line = tab + 1;
-
-		/* .. and look for the next tab */
-		tab = memchr(line, '\t', linelen);
-	} while (tab);
+	}
 
 	/*
 	 * Print out everything after the last tab without
@@ -1696,7 +1684,6 @@ static int pp_handle_indent(struct strbuf *sb, int indent,
 	 * align.
 	 */
 	strbuf_add(sb, line, linelen);
-	return 1;
 }
 
 void pp_remainder(struct pretty_print_context *pp,
@@ -1722,11 +1709,10 @@ void pp_remainder(struct pretty_print_context *pp,
 		first = 0;
 
 		strbuf_grow(sb, linelen + indent + 20);
-		if (indent) {
-			if (pp_handle_indent(sb, indent, line, linelen))
-				linelen = 0;
-		}
-		strbuf_add(sb, line, linelen);
+		if (indent)
+			pp_handle_indent(sb, indent, line, linelen);
+		else
+			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
 	}
 }

diff --git a/pretty.c b/pretty.c
index 6d657fc..717ceed 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1643,18 +1643,12 @@ static int pp_utf8_width(const char *start, const char *end)
 	return width;
 }
 
-/*
- * pp_handle_indent() prints out the intendation, and
- * the whole line (without the final newline), after
- * de-tabifying.
- */
-static void pp_handle_indent(struct strbuf *sb, int indent,
-			     const char *line, int linelen)
+
+static void strbuf_add_tabexpand(struct strbuf *sb,
+				 const char *line, int linelen)
 {
 	const char *tab;
 
-	strbuf_addchars(sb, ' ', indent);
-
 	while ((tab = memchr(line, '\t', linelen)) != NULL) {
 		int width = pp_utf8_width(line, tab);
 
@@ -1686,6 +1680,18 @@ static void pp_handle_indent(struct strbuf *sb, int indent,
 	strbuf_add(sb, line, linelen);
 }
 
+/*
+ * pp_handle_indent() prints out the intendation, and
+ * the whole line (without the final newline), after
+ * de-tabifying.
+ */
+static void pp_handle_indent(struct strbuf *sb, int indent,
+			     const char *line, int linelen)
+{
+	strbuf_addchars(sb, ' ', indent);
+	strbuf_add_tabexpand(sb, line, linelen);
+}
+
 void pp_remainder(struct pretty_print_context *pp,
 		  const char **msg_p,
 		  struct strbuf *sb,

Documentation/pretty-formats.txt, Documentation/pretty-options.txt, commit.h, pretty.c, t/t4201-shortlog.sh

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index 671cebd..173b932 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -39,6 +39,16 @@ This is designed to be as compact as possible.
 
 	      <title line>
 
+	      <full commit message, tab-expanded>
+
+* 'noexpand'
+
+	  commit <sha1>
+	  Author: <author>
+	  Date:   <author date>
+
+	      <title line>
+
 	      <full commit message>
 
 * 'full'
diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 4b659ac..7032b1a 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -3,7 +3,7 @@
 
 	Pretty-print the contents of the commit logs in a given format,
 	where '<format>' can be one of 'oneline', 'short', 'medium',
-	'full', 'fuller', 'email', 'raw', 'format:<string>'
+	'full', 'fuller', 'email', 'raw', 'noexpand', 'format:<string>'
 	and 'tformat:<string>'.  When '<format>' is none of the above,
 	and has '%placeholder' in it, it acts as if
 	'--pretty=tformat:<format>' were given.
diff --git a/commit.h b/commit.h
index 5d58be0..d511c61 100644
--- a/commit.h
+++ b/commit.h
@@ -126,6 +126,7 @@ enum cmit_fmt {
 	CMIT_FMT_RAW,
 	CMIT_FMT_MEDIUM,
 	CMIT_FMT_DEFAULT = CMIT_FMT_MEDIUM,
+	CMIT_FMT_NOEXPAND,
 	CMIT_FMT_SHORT,
 	CMIT_FMT_FULL,
 	CMIT_FMT_FULLER,
diff --git a/pretty.c b/pretty.c
index 717ceed..8b533dc 100644
--- a/pretty.c
+++ b/pretty.c
@@ -89,6 +89,7 @@ static void setup_commit_formats(void)
 	struct cmt_fmt_map builtin_formats[] = {
 		{ "raw",	CMIT_FMT_RAW,		0 },
 		{ "medium",	CMIT_FMT_MEDIUM,	0 },
+		{ "noexpand",	CMIT_FMT_NOEXPAND,	0 },
 		{ "short",	CMIT_FMT_SHORT,		0 },
 		{ "email",	CMIT_FMT_EMAIL,		0 },
 		{ "fuller",	CMIT_FMT_FULLER,	0 },
@@ -1685,11 +1686,16 @@ static void strbuf_add_tabexpand(struct strbuf *sb,
  * the whole line (without the final newline), after
  * de-tabifying.
  */
-static void pp_handle_indent(struct strbuf *sb, int indent,
+static void pp_handle_indent(struct pretty_print_context *pp,
+			     struct strbuf *sb,
+			     int indent,
 			     const char *line, int linelen)
 {
 	strbuf_addchars(sb, ' ', indent);
-	strbuf_add_tabexpand(sb, line, linelen);
+	if (pp->fmt == CMIT_FMT_MEDIUM)
+		strbuf_add_tabexpand(sb, line, linelen);
+	else
+		strbuf_add(sb, line, linelen);
 }
 
 void pp_remainder(struct pretty_print_context *pp,
@@ -1716,7 +1722,7 @@ void pp_remainder(struct pretty_print_context *pp,
 
 		strbuf_grow(sb, linelen + indent + 20);
 		if (indent)
-			pp_handle_indent(sb, indent, line, linelen);
+			pp_handle_indent(pp, sb, indent, line, linelen);
 		else
 			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 987b708..34a9fed 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -93,7 +93,7 @@ test_expect_success 'output from user-defined format is re-wrapped' '
 	test_cmp expect log.predictable
 '
 
-test_expect_failure !MINGW 'shortlog wrapping' '
+test_expect_success !MINGW 'shortlog wrapping' '
 	cat >expect <<\EOF &&
 A U Thor (5):
       Test
@@ -114,8 +114,8 @@ EOF
 	test_cmp expect out
 '
 
-test_expect_failure !MINGW 'shortlog from non-git directory' '
-	git log HEAD >log &&
+test_expect_success !MINGW 'shortlog from non-git directory' '
+	git log --pretty=noexpand HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out
 '

Documentation/pretty-formats.txt, Documentation/pretty-options.txt, commit.h, log-tree.c, pretty.c, revision.c, revision.h, t/t4201-shortlog.sh

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index 173b932..671cebd 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -39,16 +39,6 @@ This is designed to be as compact as possible.
 
 	      <title line>
 
-	      <full commit message, tab-expanded>
-
-* 'noexpand'
-
-	  commit <sha1>
-	  Author: <author>
-	  Date:   <author date>
-
-	      <title line>
-
 	      <full commit message>
 
 * 'full'
diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 7032b1a..069b927 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -3,7 +3,7 @@
 
 	Pretty-print the contents of the commit logs in a given format,
 	where '<format>' can be one of 'oneline', 'short', 'medium',
-	'full', 'fuller', 'email', 'raw', 'noexpand', 'format:<string>'
+	'full', 'fuller', 'email', 'raw', 'format:<string>'
 	and 'tformat:<string>'.  When '<format>' is none of the above,
 	and has '%placeholder' in it, it acts as if
 	'--pretty=tformat:<format>' were given.
@@ -42,6 +42,12 @@ people using 80-column terminals.
 	verbatim; this means that invalid sequences in the original
 	commit may be copied to the output.
 
+--no-expand-tabs::
+	The formats that indent the log message by 4 spaces
+	(i.e. 'medium', 'full', and 'fuller') by default show tabs
+	in the log message expanded.  This option disables the
+	expansion.
+
 ifndef::git-rev-list[]
 --notes[=<ref>]::
 	Show the notes (see linkgit:git-notes[1]) that annotate the
diff --git a/commit.h b/commit.h
index d511c61..a7ef682 100644
--- a/commit.h
+++ b/commit.h
@@ -126,7 +126,6 @@ enum cmit_fmt {
 	CMIT_FMT_RAW,
 	CMIT_FMT_MEDIUM,
 	CMIT_FMT_DEFAULT = CMIT_FMT_MEDIUM,
-	CMIT_FMT_NOEXPAND,
 	CMIT_FMT_SHORT,
 	CMIT_FMT_FULL,
 	CMIT_FMT_FULLER,
@@ -148,6 +147,7 @@ struct pretty_print_context {
 	int preserve_subject;
 	struct date_mode date_mode;
 	unsigned date_mode_explicit:1;
+	unsigned expand_tabs_in_log:1;
 	int need_8bit_cte;
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
diff --git a/log-tree.c b/log-tree.c
index 60f9839..78a5381 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -683,6 +683,7 @@ void show_log(struct rev_info *opt)
 	ctx.fmt = opt->commit_format;
 	ctx.mailmap = opt->mailmap;
 	ctx.color = opt->diffopt.use_color;
+	ctx.expand_tabs_in_log = opt->expand_tabs_in_log;
 	ctx.output_encoding = get_log_output_encoding();
 	if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
 		ctx.from_ident = &opt->from_ident;
diff --git a/pretty.c b/pretty.c
index 8b533dc..5a33b7e 100644
--- a/pretty.c
+++ b/pretty.c
@@ -16,6 +16,7 @@ static struct cmt_fmt_map {
 	const char *name;
 	enum cmit_fmt format;
 	int is_tformat;
+	int expand_tabs_in_log;
 	int is_alias;
 	const char *user_format;
 } *commit_formats;
@@ -87,14 +88,13 @@ static int git_pretty_formats_config(const char *var, const char *value, void *c
 static void setup_commit_formats(void)
 {
 	struct cmt_fmt_map builtin_formats[] = {
-		{ "raw",	CMIT_FMT_RAW,		0 },
-		{ "medium",	CMIT_FMT_MEDIUM,	0 },
-		{ "noexpand",	CMIT_FMT_NOEXPAND,	0 },
-		{ "short",	CMIT_FMT_SHORT,		0 },
-		{ "email",	CMIT_FMT_EMAIL,		0 },
-		{ "fuller",	CMIT_FMT_FULLER,	0 },
-		{ "full",	CMIT_FMT_FULL,		0 },
-		{ "oneline",	CMIT_FMT_ONELINE,	1 }
+		{ "raw",	CMIT_FMT_RAW,		0,	0 },
+		{ "medium",	CMIT_FMT_MEDIUM,	0,	1 },
+		{ "short",	CMIT_FMT_SHORT,		0,	0 },
+		{ "email",	CMIT_FMT_EMAIL,		0,	0 },
+		{ "fuller",	CMIT_FMT_FULLER,	0,	1 },
+		{ "full",	CMIT_FMT_FULL,		0,	1 },
+		{ "oneline",	CMIT_FMT_ONELINE,	1,	0 }
 	};
 	commit_formats_len = ARRAY_SIZE(builtin_formats);
 	builtin_formats_len = commit_formats_len;
@@ -173,6 +173,7 @@ void get_commit_format(const char *arg, struct rev_info *rev)
 
 	rev->commit_format = commit_format->format;
 	rev->use_terminator = commit_format->is_tformat;
+	rev->expand_tabs_in_log = commit_format->expand_tabs_in_log;
 	if (commit_format->format == CMIT_FMT_USERFORMAT) {
 		save_user_format(rev, commit_format->user_format,
 				 commit_format->is_tformat);
@@ -1687,12 +1688,11 @@ static void strbuf_add_tabexpand(struct strbuf *sb,
  * de-tabifying.
  */
 static void pp_handle_indent(struct pretty_print_context *pp,
-			     struct strbuf *sb,
-			     int indent,
+			     struct strbuf *sb, int indent,
 			     const char *line, int linelen)
 {
 	strbuf_addchars(sb, ' ', indent);
-	if (pp->fmt == CMIT_FMT_MEDIUM)
+	if (pp->expand_tabs_in_log)
 		strbuf_add_tabexpand(sb, line, linelen);
 	else
 		strbuf_add(sb, line, linelen);
diff --git a/revision.c b/revision.c
index df56fce..b0d2a36 100644
--- a/revision.c
+++ b/revision.c
@@ -1412,6 +1412,7 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->skip_count = -1;
 	revs->max_count = -1;
 	revs->max_parents = -1;
+	revs->expand_tabs_in_log = 1;
 
 	revs->commit_format = CMIT_FMT_DEFAULT;
 
@@ -1915,6 +1916,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->verbose_header = 1;
 		revs->pretty_given = 1;
 		get_commit_format(arg+9, revs);
+	} else if (!strcmp(arg, "--no-expand-tabs")) {
+		revs->expand_tabs_in_log = 0;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
diff --git a/revision.h b/revision.h
index 23857c0..0bbfe0e 100644
--- a/revision.h
+++ b/revision.h
@@ -137,6 +137,7 @@ struct rev_info {
 			abbrev_commit_given:1,
 			zero_commit:1,
 			use_terminator:1,
+			expand_tabs_in_log:1,
 			missing_newline:1,
 			date_mode_explicit:1,
 			preserve_subject:1;
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 34a9fed..2fec948 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -115,7 +115,7 @@ EOF
 '
 
 test_expect_success !MINGW 'shortlog from non-git directory' '
-	git log --pretty=noexpand HEAD >log &&
+	git log --no-expand-tabs HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out
 '

pretty.c, t/t4201-shortlog.sh

diff --git a/pretty.c b/pretty.c
index 92b2870..0b40457 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1629,6 +1629,76 @@ void pp_title_line(struct pretty_print_context *pp,
 	strbuf_release(&title);
 }
 
+static int pp_utf8_width(const char *start, const char *end)
+{
+	int width = 0;
+	size_t remain = end - start;
+
+	while (remain) {
+		int n = utf8_width(&start, &remain);
+		if (n < 0 || !start)
+			return -1;
+		width += n;
+	}
+	return width;
+}
+
+/*
+ * pp_handle_indent() prints out the intendation, and
+ * perhaps the whole line (without the final newline)
+ *
+ * Why "perhaps"? If there are tabs in the indented line
+ * it will print it out in order to de-tabify the line.
+ *
+ * But if there are no tabs, we just fall back on the
+ * normal "print the whole line".
+ */
+static int pp_handle_indent(struct strbuf *sb, int indent,
+			     const char *line, int linelen)
+{
+	const char *tab;
+
+	strbuf_addchars(sb, ' ', indent);
+
+	tab = memchr(line, '\t', linelen);
+	if (!tab)
+		return 0;
+
+	do {
+		int width = pp_utf8_width(line, tab);
+
+		/*
+		 * If it wasn't well-formed utf8, or it
+		 * had characters with badly defined
+		 * width (control characters etc), just
+		 * give up on trying to align things.
+		 */
+		if (width < 0)
+			break;
+
+		/* Output the data .. */
+		strbuf_add(sb, line, tab - line);
+
+		/* .. and the de-tabified tab */
+		strbuf_addchars(sb, ' ', 8-(width & 7));
+
+		/* Skip over the printed part .. */
+		linelen -= 1+tab-line;
+		line = tab + 1;
+
+		/* .. and look for the next tab */
+		tab = memchr(line, '\t', linelen);
+	} while (tab);
+
+	/*
+	 * Print out everything after the last tab without
+	 * worrying about width - there's nothing more to
+	 * align.
+	 */
+	strbuf_add(sb, line, linelen);
+	return 1;
+}
+
 void pp_remainder(struct pretty_print_context *pp,
 		  const char **msg_p,
 		  struct strbuf *sb,
@@ -1652,8 +1722,10 @@ void pp_remainder(struct pretty_print_context *pp,
 		first = 0;
 
 		strbuf_grow(sb, linelen + indent + 20);
-		if (indent)
-			strbuf_addchars(sb, ' ', indent);
+		if (indent) {
+			if (pp_handle_indent(sb, indent, line, linelen))
+				linelen = 0;
+		}
 		strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
 	}
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 7600a3e..987b708 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -93,7 +93,7 @@ test_expect_success 'output from user-defined format is re-wrapped' '
 	test_cmp expect log.predictable
 '
 
-test_expect_success !MINGW 'shortlog wrapping' '
+test_expect_failure !MINGW 'shortlog wrapping' '
 	cat >expect <<\EOF &&
 A U Thor (5):
       Test
@@ -114,7 +114,7 @@ EOF
 	test_cmp expect out
 '
 
-test_expect_success !MINGW 'shortlog from non-git directory' '
+test_expect_failure !MINGW 'shortlog from non-git directory' '
 	git log HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out

diff --git a/pretty.c b/pretty.c
index 0b40457..6d657fc 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1645,26 +1645,17 @@ static int pp_utf8_width(const char *start, const char *end)
 
 /*
  * pp_handle_indent() prints out the intendation, and
- * perhaps the whole line (without the final newline)
- *
- * Why "perhaps"? If there are tabs in the indented line
- * it will print it out in order to de-tabify the line.
- *
- * But if there are no tabs, we just fall back on the
- * normal "print the whole line".
+ * the whole line (without the final newline), after
+ * de-tabifying.
  */
-static int pp_handle_indent(struct strbuf *sb, int indent,
+static void pp_handle_indent(struct strbuf *sb, int indent,
 			     const char *line, int linelen)
 {
 	const char *tab;
 
 	strbuf_addchars(sb, ' ', indent);
 
-	tab = memchr(line, '\t', linelen);
-	if (!tab)
-		return 0;
-
-	do {
+	while ((tab = memchr(line, '\t', linelen)) != NULL) {
 		int width = pp_utf8_width(line, tab);
 
 		/*
@@ -1685,10 +1676,7 @@ static int pp_handle_indent(struct strbuf *sb, int indent,
 		/* Skip over the printed part .. */
 		linelen -= 1+tab-line;
 		line = tab + 1;
-
-		/* .. and look for the next tab */
-		tab = memchr(line, '\t', linelen);
-	} while (tab);
+	}
 
 	/*
 	 * Print out everything after the last tab without
@@ -1696,7 +1684,6 @@ static int pp_handle_indent(struct strbuf *sb, int indent,
 	 * align.
 	 */
 	strbuf_add(sb, line, linelen);
-	return 1;
 }
 
 void pp_remainder(struct pretty_print_context *pp,
@@ -1722,11 +1709,10 @@ void pp_remainder(struct pretty_print_context *pp,
 		first = 0;
 
 		strbuf_grow(sb, linelen + indent + 20);
-		if (indent) {
-			if (pp_handle_indent(sb, indent, line, linelen))
-				linelen = 0;
-		}
-		strbuf_add(sb, line, linelen);
+		if (indent)
+			pp_handle_indent(sb, indent, line, linelen);
+		else
+			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
 	}
 }

diff --git a/pretty.c b/pretty.c
index 6d657fc..717ceed 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1643,18 +1643,12 @@ static int pp_utf8_width(const char *start, const char *end)
 	return width;
 }
 
-/*
- * pp_handle_indent() prints out the intendation, and
- * the whole line (without the final newline), after
- * de-tabifying.
- */
-static void pp_handle_indent(struct strbuf *sb, int indent,
-			     const char *line, int linelen)
+
+static void strbuf_add_tabexpand(struct strbuf *sb,
+				 const char *line, int linelen)
 {
 	const char *tab;
 
-	strbuf_addchars(sb, ' ', indent);
-
 	while ((tab = memchr(line, '\t', linelen)) != NULL) {
 		int width = pp_utf8_width(line, tab);
 
@@ -1686,6 +1680,18 @@ static void pp_handle_indent(struct strbuf *sb, int indent,
 	strbuf_add(sb, line, linelen);
 }
 
+/*
+ * pp_handle_indent() prints out the intendation, and
+ * the whole line (without the final newline), after
+ * de-tabifying.
+ */
+static void pp_handle_indent(struct strbuf *sb, int indent,
+			     const char *line, int linelen)
+{
+	strbuf_addchars(sb, ' ', indent);
+	strbuf_add_tabexpand(sb, line, linelen);
+}
+
 void pp_remainder(struct pretty_print_context *pp,
 		  const char **msg_p,
 		  struct strbuf *sb,

commit.h, log-tree.c, pretty.c, revision.c, revision.h, t/t4201-shortlog.sh

diff --git a/commit.h b/commit.h
index 5d58be0..a7ef682 100644
--- a/commit.h
+++ b/commit.h
@@ -147,6 +147,7 @@ struct pretty_print_context {
 	int preserve_subject;
 	struct date_mode date_mode;
 	unsigned date_mode_explicit:1;
+	unsigned expand_tabs_in_log:1;
 	int need_8bit_cte;
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
diff --git a/log-tree.c b/log-tree.c
index 60f9839..78a5381 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -683,6 +683,7 @@ void show_log(struct rev_info *opt)
 	ctx.fmt = opt->commit_format;
 	ctx.mailmap = opt->mailmap;
 	ctx.color = opt->diffopt.use_color;
+	ctx.expand_tabs_in_log = opt->expand_tabs_in_log;
 	ctx.output_encoding = get_log_output_encoding();
 	if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
 		ctx.from_ident = &opt->from_ident;
diff --git a/pretty.c b/pretty.c
index 717ceed..5a33b7e 100644
--- a/pretty.c
+++ b/pretty.c
@@ -16,6 +16,7 @@ static struct cmt_fmt_map {
 	const char *name;
 	enum cmit_fmt format;
 	int is_tformat;
+	int expand_tabs_in_log;
 	int is_alias;
 	const char *user_format;
 } *commit_formats;
@@ -87,13 +88,13 @@ static int git_pretty_formats_config(const char *var, const char *value, void *c
 static void setup_commit_formats(void)
 {
 	struct cmt_fmt_map builtin_formats[] = {
-		{ "raw",	CMIT_FMT_RAW,		0 },
-		{ "medium",	CMIT_FMT_MEDIUM,	0 },
-		{ "short",	CMIT_FMT_SHORT,		0 },
-		{ "email",	CMIT_FMT_EMAIL,		0 },
-		{ "fuller",	CMIT_FMT_FULLER,	0 },
-		{ "full",	CMIT_FMT_FULL,		0 },
-		{ "oneline",	CMIT_FMT_ONELINE,	1 }
+		{ "raw",	CMIT_FMT_RAW,		0,	0 },
+		{ "medium",	CMIT_FMT_MEDIUM,	0,	1 },
+		{ "short",	CMIT_FMT_SHORT,		0,	0 },
+		{ "email",	CMIT_FMT_EMAIL,		0,	0 },
+		{ "fuller",	CMIT_FMT_FULLER,	0,	1 },
+		{ "full",	CMIT_FMT_FULL,		0,	1 },
+		{ "oneline",	CMIT_FMT_ONELINE,	1,	0 }
 	};
 	commit_formats_len = ARRAY_SIZE(builtin_formats);
 	builtin_formats_len = commit_formats_len;
@@ -172,6 +173,7 @@ void get_commit_format(const char *arg, struct rev_info *rev)
 
 	rev->commit_format = commit_format->format;
 	rev->use_terminator = commit_format->is_tformat;
+	rev->expand_tabs_in_log = commit_format->expand_tabs_in_log;
 	if (commit_format->format == CMIT_FMT_USERFORMAT) {
 		save_user_format(rev, commit_format->user_format,
 				 commit_format->is_tformat);
@@ -1685,11 +1687,15 @@ static void strbuf_add_tabexpand(struct strbuf *sb,
  * the whole line (without the final newline), after
  * de-tabifying.
  */
-static void pp_handle_indent(struct strbuf *sb, int indent,
+static void pp_handle_indent(struct pretty_print_context *pp,
+			     struct strbuf *sb, int indent,
 			     const char *line, int linelen)
 {
 	strbuf_addchars(sb, ' ', indent);
-	strbuf_add_tabexpand(sb, line, linelen);
+	if (pp->expand_tabs_in_log)
+		strbuf_add_tabexpand(sb, line, linelen);
+	else
+		strbuf_add(sb, line, linelen);
 }
 
 void pp_remainder(struct pretty_print_context *pp,
@@ -1716,7 +1722,7 @@ void pp_remainder(struct pretty_print_context *pp,
 
 		strbuf_grow(sb, linelen + indent + 20);
 		if (indent)
-			pp_handle_indent(sb, indent, line, linelen);
+			pp_handle_indent(pp, sb, indent, line, linelen);
 		else
 			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
diff --git a/revision.c b/revision.c
index df56fce..8827d9f 100644
--- a/revision.c
+++ b/revision.c
@@ -1412,6 +1412,7 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->skip_count = -1;
 	revs->max_count = -1;
 	revs->max_parents = -1;
+	revs->expand_tabs_in_log = 1;
 
 	revs->commit_format = CMIT_FMT_DEFAULT;
 
diff --git a/revision.h b/revision.h
index 23857c0..0bbfe0e 100644
--- a/revision.h
+++ b/revision.h
@@ -137,6 +137,7 @@ struct rev_info {
 			abbrev_commit_given:1,
 			zero_commit:1,
 			use_terminator:1,
+			expand_tabs_in_log:1,
 			missing_newline:1,
 			date_mode_explicit:1,
 			preserve_subject:1;
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 987b708..d1e8259 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -93,7 +93,7 @@ test_expect_success 'output from user-defined format is re-wrapped' '
 	test_cmp expect log.predictable
 '
 
-test_expect_failure !MINGW 'shortlog wrapping' '
+test_expect_success !MINGW 'shortlog wrapping' '
 	cat >expect <<\EOF &&
 A U Thor (5):
       Test

Documentation/pretty-options.txt, revision.c, t/t4201-shortlog.sh

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 4b659ac..069b927 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -42,6 +42,12 @@ people using 80-column terminals.
 	verbatim; this means that invalid sequences in the original
 	commit may be copied to the output.
 
+--no-expand-tabs::
+	The formats that indent the log message by 4 spaces
+	(i.e. 'medium', 'full', and 'fuller') by default show tabs
+	in the log message expanded.  This option disables the
+	expansion.
+
 ifndef::git-rev-list[]
 --notes[=<ref>]::
 	Show the notes (see linkgit:git-notes[1]) that annotate the
diff --git a/revision.c b/revision.c
index 8827d9f..b0d2a36 100644
--- a/revision.c
+++ b/revision.c
@@ -1916,6 +1916,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->verbose_header = 1;
 		revs->pretty_given = 1;
 		get_commit_format(arg+9, revs);
+	} else if (!strcmp(arg, "--no-expand-tabs")) {
+		revs->expand_tabs_in_log = 0;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index d1e8259..2fec948 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -114,8 +114,8 @@ EOF
 	test_cmp expect out
 '
 
-test_expect_failure !MINGW 'shortlog from non-git directory' '
-	git log HEAD >log &&
+test_expect_success !MINGW 'shortlog from non-git directory' '
+	git log --no-expand-tabs HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out
 '

Documentation/config.txt, cache.h, config.c, environment.c, pretty.c, t/t4201-shortlog.sh

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 2cd6bdd..611f5e4 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1915,6 +1915,10 @@ log.showRoot::
 	Tools like linkgit:git-log[1] or linkgit:git-whatchanged[1], which
 	normally hide the root commit will now show it. True by default.

+log.tabWidth::
+	Sets the width of a TAB.  If 0, no TAB expansion is done.
+	8 by default.
+
 log.mailmap::
 	If true, makes linkgit:git-log[1], linkgit:git-show[1], and
 	linkgit:git-whatchanged[1] assume `--use-mailmap`.
diff --git a/cache.h b/cache.h
index b829410..fd115d2 100644
--- a/cache.h
+++ b/cache.h
@@ -649,6 +649,7 @@ extern int ignore_case;
 extern int assume_unchanged;
 extern int prefer_symlink_refs;
 extern int log_all_ref_updates;
+extern unsigned log_tab_width;
 extern int warn_ambiguous_refs;
 extern int warn_on_object_refname_ambiguity;
 extern int shared_repository;
diff --git a/config.c b/config.c
index 9ba40bc..e6aadfe 100644
--- a/config.c
+++ b/config.c
@@ -1030,6 +1030,11 @@ int git_default_config(const char *var, const char
*value, void *dummy)
 		pack_size_limit_cfg = git_config_ulong(var, value);
 		return 0;
 	}
+
+	if (!strcmp(var, "log.tabwidth")) {
+		log_tab_width = (unsigned)git_config_ulong(var, value);
+		return 0;
+	}
 	/* Add other config variables here and to Documentation/config.txt. */
 	return 0;
 }
diff --git a/environment.c b/environment.c
index 6dec9d0..3c72b44 100644
--- a/environment.c
+++ b/environment.c
@@ -21,6 +21,7 @@ int ignore_case;
 int assume_unchanged;
 int prefer_symlink_refs;
 int is_bare_repository_cfg = -1; /* unspecified */
+unsigned log_tab_width = 8;
 int log_all_ref_updates = -1; /* unspecified */
 int warn_ambiguous_refs = 1;
 int warn_on_object_refname_ambiguity = 1;
diff --git a/pretty.c b/pretty.c
index 5a33b7e..1d92c55 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1667,7 +1667,7 @@ static void strbuf_add_tabexpand(struct strbuf *sb,
 		strbuf_add(sb, line, tab - line);

 		/* .. and the de-tabified tab */
-		strbuf_addchars(sb, ' ', 8-(width & 7));
+		strbuf_addchars(sb, ' ', log_tab_width - (width % log_tab_width));

 		/* Skip over the printed part .. */
 		linelen -= 1+tab-line;
@@ -1692,7 +1692,7 @@ static void pp_handle_indent(struct pretty_print_context *pp,
 			     const char *line, int linelen)
 {
 	strbuf_addchars(sb, ' ', indent);
-	if (pp->expand_tabs_in_log)
+	if (pp->expand_tabs_in_log && log_tab_width)
 		strbuf_add_tabexpand(sb, line, linelen);
 	else
 		strbuf_add(sb, line, linelen);
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 96233ca..9235a2e 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -114,8 +114,8 @@ EOF
 	test_cmp expect out
 '

-test_expect_failure !MINGW 'shortlog from non-git directory' '
-	git log HEAD >log &&
+test_expect_success !MINGW 'shortlog from non-git directory' '
+	git -c log.tabwidth=0 log HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out
 '

Documentation/pretty-options.txt, commit.h, log-tree.c, pretty.c, revision.c, revision.h

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 4b659ac..4fb5c76 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -42,6 +42,12 @@ people using 80-column terminals.
 	verbatim; this means that invalid sequences in the original
 	commit may be copied to the output.
 
+--expand-tabs::
+	Perform a tab expansion (replace each tab with enough number
+	of spaces to fill to the next display column that is
+	multiple of 8) in the log message before using the message
+	to show in the output.
+
 ifndef::git-rev-list[]
 --notes[=<ref>]::
 	Show the notes (see linkgit:git-notes[1]) that annotate the
diff --git a/commit.h b/commit.h
index 5d58be0..a7ef682 100644
--- a/commit.h
+++ b/commit.h
@@ -147,6 +147,7 @@ struct pretty_print_context {
 	int preserve_subject;
 	struct date_mode date_mode;
 	unsigned date_mode_explicit:1;
+	unsigned expand_tabs_in_log:1;
 	int need_8bit_cte;
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
diff --git a/log-tree.c b/log-tree.c
index 60f9839..78a5381 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -683,6 +683,7 @@ void show_log(struct rev_info *opt)
 	ctx.fmt = opt->commit_format;
 	ctx.mailmap = opt->mailmap;
 	ctx.color = opt->diffopt.use_color;
+	ctx.expand_tabs_in_log = opt->expand_tabs_in_log;
 	ctx.output_encoding = get_log_output_encoding();
 	if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
 		ctx.from_ident = &opt->from_ident;
diff --git a/pretty.c b/pretty.c
index 92b2870..c8b075d 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1629,6 +1629,72 @@ void pp_title_line(struct pretty_print_context *pp,
 	strbuf_release(&title);
 }
 
+static int pp_utf8_width(const char *start, const char *end)
+{
+	int width = 0;
+	size_t remain = end - start;
+
+	while (remain) {
+		int n = utf8_width(&start, &remain);
+		if (n < 0 || !start)
+			return -1;
+		width += n;
+	}
+	return width;
+}
+
+static void strbuf_add_tabexpand(struct strbuf *sb,
+				 const char *line, int linelen)
+{
+	const char *tab;
+
+	while ((tab = memchr(line, '\t', linelen)) != NULL) {
+		int width = pp_utf8_width(line, tab);
+
+		/*
+		 * If it wasn't well-formed utf8, or it
+		 * had characters with badly defined
+		 * width (control characters etc), just
+		 * give up on trying to align things.
+		 */
+		if (width < 0)
+			break;
+
+		/* Output the data .. */
+		strbuf_add(sb, line, tab - line);
+
+		/* .. and the de-tabified tab */
+		strbuf_addchars(sb, ' ', 8 - (width % 8));
+
+		/* Skip over the printed part .. */
+		linelen -= tab + 1 - line;
+		line = tab + 1;
+	}
+
+	/*
+	 * Print out everything after the last tab without
+	 * worrying about width - there's nothing more to
+	 * align.
+	 */
+	strbuf_add(sb, line, linelen);
+}
+
+/*
+ * pp_handle_indent() prints out the intendation, and
+ * the whole line (without the final newline), after
+ * de-tabifying.
+ */
+static void pp_handle_indent(struct pretty_print_context *pp,
+			     struct strbuf *sb, int indent,
+			     const char *line, int linelen)
+{
+	strbuf_addchars(sb, ' ', indent);
+	if (pp->expand_tabs_in_log)
+		strbuf_add_tabexpand(sb, line, linelen);
+	else
+		strbuf_add(sb, line, linelen);
+}
+
 void pp_remainder(struct pretty_print_context *pp,
 		  const char **msg_p,
 		  struct strbuf *sb,
@@ -1653,8 +1719,9 @@ void pp_remainder(struct pretty_print_context *pp,
 
 		strbuf_grow(sb, linelen + indent + 20);
 		if (indent)
-			strbuf_addchars(sb, ' ', indent);
-		strbuf_add(sb, line, linelen);
+			pp_handle_indent(pp, sb, indent, line, linelen);
+		else
+			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
 	}
 }
diff --git a/revision.c b/revision.c
index df56fce..e662230 100644
--- a/revision.c
+++ b/revision.c
@@ -1915,6 +1915,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->verbose_header = 1;
 		revs->pretty_given = 1;
 		get_commit_format(arg+9, revs);
+	} else if (!strcmp(arg, "--expand-tabs")) {
+		revs->expand_tabs_in_log = 1;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
diff --git a/revision.h b/revision.h
index 23857c0..4079753 100644
--- a/revision.h
+++ b/revision.h
@@ -133,6 +133,7 @@ struct rev_info {
 			show_notes_given:1,
 			show_signature:1,
 			pretty_given:1,
+			expand_tabs_in_log:1,
 			abbrev_commit:1,
 			abbrev_commit_given:1,
 			zero_commit:1,

Documentation/pretty-options.txt, pretty.c, revision.c, t/t4201-shortlog.sh

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 4fb5c76..23967b6 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -43,10 +43,16 @@ people using 80-column terminals.
 	commit may be copied to the output.
 
 --expand-tabs::
+--no-expand-tabs::
 	Perform a tab expansion (replace each tab with enough number
 	of spaces to fill to the next display column that is
 	multiple of 8) in the log message before using the message
 	to show in the output.
++
+By default, tabs are expanded in pretty formats that indent the log
+message by 4 spaces (i.e.  'medium', which is the default, 'full',
+and "fuller').  `--no-expand-tabs` option can be used to disable
+this.
 
 ifndef::git-rev-list[]
 --notes[=<ref>]::
diff --git a/pretty.c b/pretty.c
index c8b075d..de22a8c 100644
--- a/pretty.c
+++ b/pretty.c
@@ -16,6 +16,7 @@ static struct cmt_fmt_map {
 	const char *name;
 	enum cmit_fmt format;
 	int is_tformat;
+	int expand_tabs_in_log;
 	int is_alias;
 	const char *user_format;
 } *commit_formats;
@@ -87,13 +88,13 @@ static int git_pretty_formats_config(const char *var, const char *value, void *c
 static void setup_commit_formats(void)
 {
 	struct cmt_fmt_map builtin_formats[] = {
-		{ "raw",	CMIT_FMT_RAW,		0 },
-		{ "medium",	CMIT_FMT_MEDIUM,	0 },
-		{ "short",	CMIT_FMT_SHORT,		0 },
-		{ "email",	CMIT_FMT_EMAIL,		0 },
-		{ "fuller",	CMIT_FMT_FULLER,	0 },
-		{ "full",	CMIT_FMT_FULL,		0 },
-		{ "oneline",	CMIT_FMT_ONELINE,	1 }
+		{ "raw",	CMIT_FMT_RAW,		0,	0 },
+		{ "medium",	CMIT_FMT_MEDIUM,	0,	1 },
+		{ "short",	CMIT_FMT_SHORT,		0,	0 },
+		{ "email",	CMIT_FMT_EMAIL,		0,	0 },
+		{ "fuller",	CMIT_FMT_FULLER,	0,	1 },
+		{ "full",	CMIT_FMT_FULL,		0,	1 },
+		{ "oneline",	CMIT_FMT_ONELINE,	1,	0 }
 	};
 	commit_formats_len = ARRAY_SIZE(builtin_formats);
 	builtin_formats_len = commit_formats_len;
@@ -172,6 +173,7 @@ void get_commit_format(const char *arg, struct rev_info *rev)
 
 	rev->commit_format = commit_format->format;
 	rev->use_terminator = commit_format->is_tformat;
+	rev->expand_tabs_in_log = commit_format->expand_tabs_in_log;
 	if (commit_format->format == CMIT_FMT_USERFORMAT) {
 		save_user_format(rev, commit_format->user_format,
 				 commit_format->is_tformat);
diff --git a/revision.c b/revision.c
index e662230..b1d767a 100644
--- a/revision.c
+++ b/revision.c
@@ -1412,6 +1412,7 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->skip_count = -1;
 	revs->max_count = -1;
 	revs->max_parents = -1;
+	revs->expand_tabs_in_log = 1;
 
 	revs->commit_format = CMIT_FMT_DEFAULT;
 
@@ -1917,6 +1918,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		get_commit_format(arg+9, revs);
 	} else if (!strcmp(arg, "--expand-tabs")) {
 		revs->expand_tabs_in_log = 1;
+	} else if (!strcmp(arg, "--no-expand-tabs")) {
+		revs->expand_tabs_in_log = 0;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 7600a3e..2fec948 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -115,7 +115,7 @@ EOF
 '
 
 test_expect_success !MINGW 'shortlog from non-git directory' '
-	git log HEAD >log &&
+	git log --no-expand-tabs HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out
 '

Documentation/pretty-options.txt, commit.h, pretty.c, revision.c, revision.h

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 23967b6..8a944b1 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -42,17 +42,19 @@ people using 80-column terminals.
 	verbatim; this means that invalid sequences in the original
 	commit may be copied to the output.
 
+--expand-tabs=<n>::
 --expand-tabs::
 --no-expand-tabs::
 	Perform a tab expansion (replace each tab with enough number
 	of spaces to fill to the next display column that is
-	multiple of 8) in the log message before using the message
-	to show in the output.
+	multiple of '<n>') in the log message before using the message
+	to show in the output.  `--expand-tabs` is a short-hand for
+	`--expand-tabs=8`, and `--no-expand-tabs` is a short-hand for
+	`--expand-tabs=0`, which disables tab expansion.
 +
 By default, tabs are expanded in pretty formats that indent the log
 message by 4 spaces (i.e.  'medium', which is the default, 'full',
-and "fuller').  `--no-expand-tabs` option can be used to disable
-this.
+and "fuller').
 
 ifndef::git-rev-list[]
 --notes[=<ref>]::
diff --git a/commit.h b/commit.h
index a7ef682..2185c8d 100644
--- a/commit.h
+++ b/commit.h
@@ -147,7 +147,7 @@ struct pretty_print_context {
 	int preserve_subject;
 	struct date_mode date_mode;
 	unsigned date_mode_explicit:1;
-	unsigned expand_tabs_in_log:1;
+	unsigned expand_tabs_in_log;
 	int need_8bit_cte;
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
diff --git a/pretty.c b/pretty.c
index de22a8c..b340ecd 100644
--- a/pretty.c
+++ b/pretty.c
@@ -89,11 +89,11 @@ static void setup_commit_formats(void)
 {
 	struct cmt_fmt_map builtin_formats[] = {
 		{ "raw",	CMIT_FMT_RAW,		0,	0 },
-		{ "medium",	CMIT_FMT_MEDIUM,	0,	1 },
+		{ "medium",	CMIT_FMT_MEDIUM,	0,	8 },
 		{ "short",	CMIT_FMT_SHORT,		0,	0 },
 		{ "email",	CMIT_FMT_EMAIL,		0,	0 },
-		{ "fuller",	CMIT_FMT_FULLER,	0,	1 },
-		{ "full",	CMIT_FMT_FULL,		0,	1 },
+		{ "fuller",	CMIT_FMT_FULLER,	0,	8 },
+		{ "full",	CMIT_FMT_FULL,		0,	8 },
 		{ "oneline",	CMIT_FMT_ONELINE,	1,	0 }
 	};
 	commit_formats_len = ARRAY_SIZE(builtin_formats);
@@ -1645,7 +1645,7 @@ static int pp_utf8_width(const char *start, const char *end)
 	return width;
 }
 
-static void strbuf_add_tabexpand(struct strbuf *sb,
+static void strbuf_add_tabexpand(struct strbuf *sb, int tabwidth,
 				 const char *line, int linelen)
 {
 	const char *tab;
@@ -1666,7 +1666,7 @@ static void strbuf_add_tabexpand(struct strbuf *sb,
 		strbuf_add(sb, line, tab - line);
 
 		/* .. and the de-tabified tab */
-		strbuf_addchars(sb, ' ', 8 - (width % 8));
+		strbuf_addchars(sb, ' ', tabwidth - (width % tabwidth));
 
 		/* Skip over the printed part .. */
 		linelen -= tab + 1 - line;
@@ -1692,7 +1692,7 @@ static void pp_handle_indent(struct pretty_print_context *pp,
 {
 	strbuf_addchars(sb, ' ', indent);
 	if (pp->expand_tabs_in_log)
-		strbuf_add_tabexpand(sb, line, linelen);
+		strbuf_add_tabexpand(sb, pp->expand_tabs_in_log, line, linelen);
 	else
 		strbuf_add(sb, line, linelen);
 }
diff --git a/revision.c b/revision.c
index b1d767a..4f9ecbe 100644
--- a/revision.c
+++ b/revision.c
@@ -1412,7 +1412,7 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->skip_count = -1;
 	revs->max_count = -1;
 	revs->max_parents = -1;
-	revs->expand_tabs_in_log = 1;
+	revs->expand_tabs_in_log = 8;
 
 	revs->commit_format = CMIT_FMT_DEFAULT;
 
@@ -1917,9 +1917,14 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->pretty_given = 1;
 		get_commit_format(arg+9, revs);
 	} else if (!strcmp(arg, "--expand-tabs")) {
-		revs->expand_tabs_in_log = 1;
+		revs->expand_tabs_in_log = 8;
 	} else if (!strcmp(arg, "--no-expand-tabs")) {
 		revs->expand_tabs_in_log = 0;
+	} else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
+		int val;
+		if (strtol_i(arg, 10, &val) < 0 || val < 0)
+			die("'%s': not a non-negative integer", arg);
+		revs->expand_tabs_in_log = val;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
diff --git a/revision.h b/revision.h
index 4079753..cf6615a 100644
--- a/revision.h
+++ b/revision.h
@@ -133,7 +133,6 @@ struct rev_info {
 			show_notes_given:1,
 			show_signature:1,
 			pretty_given:1,
-			expand_tabs_in_log:1,
 			abbrev_commit:1,
 			abbrev_commit_given:1,
 			zero_commit:1,
@@ -149,7 +148,7 @@ struct rev_info {
 			linear:1;
 
 	struct date_mode date_mode;
-
+	unsigned int	expand_tabs_in_log;
 	unsigned int	abbrev;
 	enum cmit_fmt	commit_format;
 	struct log_info *loginfo;

Documentation/pretty-options.txt, commit.h, log-tree.c, pretty.c, revision.c, revision.h

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 4b659ac..d820653 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -42,6 +42,11 @@ people using 80-column terminals.
 	verbatim; this means that invalid sequences in the original
 	commit may be copied to the output.
 
+--expand-tabs::
+	Perform a tab expansion (replace each tab with enough spaces
+	to fill to the next display column that is multiple of 8)
+	in the log message before showing it in the output.
+
 ifndef::git-rev-list[]
 --notes[=<ref>]::
 	Show the notes (see linkgit:git-notes[1]) that annotate the
diff --git a/commit.h b/commit.h
index 5d58be0..a7ef682 100644
--- a/commit.h
+++ b/commit.h
@@ -147,6 +147,7 @@ struct pretty_print_context {
 	int preserve_subject;
 	struct date_mode date_mode;
 	unsigned date_mode_explicit:1;
+	unsigned expand_tabs_in_log:1;
 	int need_8bit_cte;
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
diff --git a/log-tree.c b/log-tree.c
index 60f9839..78a5381 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -683,6 +683,7 @@ void show_log(struct rev_info *opt)
 	ctx.fmt = opt->commit_format;
 	ctx.mailmap = opt->mailmap;
 	ctx.color = opt->diffopt.use_color;
+	ctx.expand_tabs_in_log = opt->expand_tabs_in_log;
 	ctx.output_encoding = get_log_output_encoding();
 	if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
 		ctx.from_ident = &opt->from_ident;
diff --git a/pretty.c b/pretty.c
index 92b2870..c8b075d 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1629,6 +1629,72 @@ void pp_title_line(struct pretty_print_context *pp,
 	strbuf_release(&title);
 }
 
+static int pp_utf8_width(const char *start, const char *end)
+{
+	int width = 0;
+	size_t remain = end - start;
+
+	while (remain) {
+		int n = utf8_width(&start, &remain);
+		if (n < 0 || !start)
+			return -1;
+		width += n;
+	}
+	return width;
+}
+
+static void strbuf_add_tabexpand(struct strbuf *sb,
+				 const char *line, int linelen)
+{
+	const char *tab;
+
+	while ((tab = memchr(line, '\t', linelen)) != NULL) {
+		int width = pp_utf8_width(line, tab);
+
+		/*
+		 * If it wasn't well-formed utf8, or it
+		 * had characters with badly defined
+		 * width (control characters etc), just
+		 * give up on trying to align things.
+		 */
+		if (width < 0)
+			break;
+
+		/* Output the data .. */
+		strbuf_add(sb, line, tab - line);
+
+		/* .. and the de-tabified tab */
+		strbuf_addchars(sb, ' ', 8 - (width % 8));
+
+		/* Skip over the printed part .. */
+		linelen -= tab + 1 - line;
+		line = tab + 1;
+	}
+
+	/*
+	 * Print out everything after the last tab without
+	 * worrying about width - there's nothing more to
+	 * align.
+	 */
+	strbuf_add(sb, line, linelen);
+}
+
+/*
+ * pp_handle_indent() prints out the intendation, and
+ * the whole line (without the final newline), after
+ * de-tabifying.
+ */
+static void pp_handle_indent(struct pretty_print_context *pp,
+			     struct strbuf *sb, int indent,
+			     const char *line, int linelen)
+{
+	strbuf_addchars(sb, ' ', indent);
+	if (pp->expand_tabs_in_log)
+		strbuf_add_tabexpand(sb, line, linelen);
+	else
+		strbuf_add(sb, line, linelen);
+}
+
 void pp_remainder(struct pretty_print_context *pp,
 		  const char **msg_p,
 		  struct strbuf *sb,
@@ -1653,8 +1719,9 @@ void pp_remainder(struct pretty_print_context *pp,
 
 		strbuf_grow(sb, linelen + indent + 20);
 		if (indent)
-			strbuf_addchars(sb, ' ', indent);
-		strbuf_add(sb, line, linelen);
+			pp_handle_indent(pp, sb, indent, line, linelen);
+		else
+			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
 	}
 }
diff --git a/revision.c b/revision.c
index df56fce..e662230 100644
--- a/revision.c
+++ b/revision.c
@@ -1915,6 +1915,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->verbose_header = 1;
 		revs->pretty_given = 1;
 		get_commit_format(arg+9, revs);
+	} else if (!strcmp(arg, "--expand-tabs")) {
+		revs->expand_tabs_in_log = 1;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
diff --git a/revision.h b/revision.h
index 23857c0..4079753 100644
--- a/revision.h
+++ b/revision.h
@@ -133,6 +133,7 @@ struct rev_info {
 			show_notes_given:1,
 			show_signature:1,
 			pretty_given:1,
+			expand_tabs_in_log:1,
 			abbrev_commit:1,
 			abbrev_commit_given:1,
 			zero_commit:1,

Documentation/pretty-options.txt, builtin/log.c, pretty.c, revision.c, revision.h, t/t4201-shortlog.sh

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index d820653..edbb02f 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -43,9 +43,15 @@ people using 80-column terminals.
 	commit may be copied to the output.
 
 --expand-tabs::
+--no-expand-tabs::
 	Perform a tab expansion (replace each tab with enough spaces
 	to fill to the next display column that is multiple of 8)
 	in the log message before showing it in the output.
++
+By default, tabs are expanded in pretty formats that indent the log
+message by 4 spaces (i.e.  'medium', which is the default, 'full',
+and 'fuller').  `--no-expand-tabs` option can be used to disable
+this.
 
 ifndef::git-rev-list[]
 --notes[=<ref>]::
diff --git a/builtin/log.c b/builtin/log.c
index e00cea7..e5775ae 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1281,6 +1281,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	git_config(git_format_config, NULL);
 	init_revisions(&rev, prefix);
 	rev.commit_format = CMIT_FMT_EMAIL;
+	rev.expand_tabs_in_log_default = 0;
 	rev.verbose_header = 1;
 	rev.diff = 1;
 	rev.max_parents = 1;
diff --git a/pretty.c b/pretty.c
index c8b075d..b7938e0 100644
--- a/pretty.c
+++ b/pretty.c
@@ -16,6 +16,7 @@ static struct cmt_fmt_map {
 	const char *name;
 	enum cmit_fmt format;
 	int is_tformat;
+	int expand_tabs_in_log;
 	int is_alias;
 	const char *user_format;
 } *commit_formats;
@@ -87,13 +88,13 @@ static int git_pretty_formats_config(const char *var, const char *value, void *c
 static void setup_commit_formats(void)
 {
 	struct cmt_fmt_map builtin_formats[] = {
-		{ "raw",	CMIT_FMT_RAW,		0 },
-		{ "medium",	CMIT_FMT_MEDIUM,	0 },
-		{ "short",	CMIT_FMT_SHORT,		0 },
-		{ "email",	CMIT_FMT_EMAIL,		0 },
-		{ "fuller",	CMIT_FMT_FULLER,	0 },
-		{ "full",	CMIT_FMT_FULL,		0 },
-		{ "oneline",	CMIT_FMT_ONELINE,	1 }
+		{ "raw",	CMIT_FMT_RAW,		0,	0 },
+		{ "medium",	CMIT_FMT_MEDIUM,	0,	1 },
+		{ "short",	CMIT_FMT_SHORT,		0,	0 },
+		{ "email",	CMIT_FMT_EMAIL,		0,	0 },
+		{ "fuller",	CMIT_FMT_FULLER,	0,	1 },
+		{ "full",	CMIT_FMT_FULL,		0,	1 },
+		{ "oneline",	CMIT_FMT_ONELINE,	1,	0 }
 	};
 	commit_formats_len = ARRAY_SIZE(builtin_formats);
 	builtin_formats_len = commit_formats_len;
@@ -172,6 +173,7 @@ void get_commit_format(const char *arg, struct rev_info *rev)
 
 	rev->commit_format = commit_format->format;
 	rev->use_terminator = commit_format->is_tformat;
+	rev->expand_tabs_in_log_default = commit_format->expand_tabs_in_log;
 	if (commit_format->format == CMIT_FMT_USERFORMAT) {
 		save_user_format(rev, commit_format->user_format,
 				 commit_format->is_tformat);
@@ -1720,6 +1722,8 @@ void pp_remainder(struct pretty_print_context *pp,
 		strbuf_grow(sb, linelen + indent + 20);
 		if (indent)
 			pp_handle_indent(pp, sb, indent, line, linelen);
+		else if (pp->expand_tabs_in_log)
+			strbuf_add_tabexpand(sb, line, linelen);
 		else
 			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
diff --git a/revision.c b/revision.c
index e662230..da53b6c 100644
--- a/revision.c
+++ b/revision.c
@@ -1412,8 +1412,10 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->skip_count = -1;
 	revs->max_count = -1;
 	revs->max_parents = -1;
+	revs->expand_tabs_in_log = -1;
 
 	revs->commit_format = CMIT_FMT_DEFAULT;
+	revs->expand_tabs_in_log_default = 1;
 
 	init_grep_defaults();
 	grep_init(&revs->grep_filter, prefix);
@@ -1917,6 +1919,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		get_commit_format(arg+9, revs);
 	} else if (!strcmp(arg, "--expand-tabs")) {
 		revs->expand_tabs_in_log = 1;
+	} else if (!strcmp(arg, "--no-expand-tabs")) {
+		revs->expand_tabs_in_log = 0;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
@@ -2390,6 +2394,9 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 	if (revs->first_parent_only && revs->bisect)
 		die(_("--first-parent is incompatible with --bisect"));
 
+	if (revs->expand_tabs_in_log < 0)
+		revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
+
 	return left;
 }
 
diff --git a/revision.h b/revision.h
index 4079753..6cc36b4 100644
--- a/revision.h
+++ b/revision.h
@@ -133,7 +133,6 @@ struct rev_info {
 			show_notes_given:1,
 			show_signature:1,
 			pretty_given:1,
-			expand_tabs_in_log:1,
 			abbrev_commit:1,
 			abbrev_commit_given:1,
 			zero_commit:1,
@@ -149,6 +148,8 @@ struct rev_info {
 			linear:1;
 
 	struct date_mode date_mode;
+	int		expand_tabs_in_log; /* unset if negative */
+	int		expand_tabs_in_log_default;
 
 	unsigned int	abbrev;
 	enum cmit_fmt	commit_format;
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 7600a3e..2fec948 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -115,7 +115,7 @@ EOF
 '
 
 test_expect_success !MINGW 'shortlog from non-git directory' '
-	git log HEAD >log &&
+	git log --no-expand-tabs HEAD >log &&
 	GIT_DIR=non-existing git shortlog -w <log >out &&
 	test_cmp expect out
 '

Documentation/pretty-options.txt, commit.h, pretty.c, revision.c

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index edbb02f..93ad1cd 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -42,16 +42,19 @@ people using 80-column terminals.
 	verbatim; this means that invalid sequences in the original
 	commit may be copied to the output.
 
+--expand-tabs=<n>::
 --expand-tabs::
 --no-expand-tabs::
 	Perform a tab expansion (replace each tab with enough spaces
-	to fill to the next display column that is multiple of 8)
+	to fill to the next display column that is multiple of '<n>')
 	in the log message before showing it in the output.
+	`--expand-tabs` is a short-hand for `--expand-tabs=8`, and
+	`--no-expand-tabs` is a short-hand for `--expand-tabs=0`,
+	which disables tab expansion.
 +
 By default, tabs are expanded in pretty formats that indent the log
 message by 4 spaces (i.e.  'medium', which is the default, 'full',
-and 'fuller').  `--no-expand-tabs` option can be used to disable
-this.
+and 'fuller').
 
 ifndef::git-rev-list[]
 --notes[=<ref>]::
diff --git a/commit.h b/commit.h
index a7ef682..b06db4d 100644
--- a/commit.h
+++ b/commit.h
@@ -147,7 +147,7 @@ struct pretty_print_context {
 	int preserve_subject;
 	struct date_mode date_mode;
 	unsigned date_mode_explicit:1;
-	unsigned expand_tabs_in_log:1;
+	int expand_tabs_in_log;
 	int need_8bit_cte;
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
diff --git a/pretty.c b/pretty.c
index b7938e0..87c4497 100644
--- a/pretty.c
+++ b/pretty.c
@@ -89,11 +89,11 @@ static void setup_commit_formats(void)
 {
 	struct cmt_fmt_map builtin_formats[] = {
 		{ "raw",	CMIT_FMT_RAW,		0,	0 },
-		{ "medium",	CMIT_FMT_MEDIUM,	0,	1 },
+		{ "medium",	CMIT_FMT_MEDIUM,	0,	8 },
 		{ "short",	CMIT_FMT_SHORT,		0,	0 },
 		{ "email",	CMIT_FMT_EMAIL,		0,	0 },
-		{ "fuller",	CMIT_FMT_FULLER,	0,	1 },
-		{ "full",	CMIT_FMT_FULL,		0,	1 },
+		{ "fuller",	CMIT_FMT_FULLER,	0,	8 },
+		{ "full",	CMIT_FMT_FULL,		0,	8 },
 		{ "oneline",	CMIT_FMT_ONELINE,	1,	0 }
 	};
 	commit_formats_len = ARRAY_SIZE(builtin_formats);
@@ -1645,7 +1645,7 @@ static int pp_utf8_width(const char *start, const char *end)
 	return width;
 }
 
-static void strbuf_add_tabexpand(struct strbuf *sb,
+static void strbuf_add_tabexpand(struct strbuf *sb, int tabwidth,
 				 const char *line, int linelen)
 {
 	const char *tab;
@@ -1666,7 +1666,7 @@ static void strbuf_add_tabexpand(struct strbuf *sb,
 		strbuf_add(sb, line, tab - line);
 
 		/* .. and the de-tabified tab */
-		strbuf_addchars(sb, ' ', 8 - (width % 8));
+		strbuf_addchars(sb, ' ', tabwidth - (width % tabwidth));
 
 		/* Skip over the printed part .. */
 		linelen -= tab + 1 - line;
@@ -1692,7 +1692,7 @@ static void pp_handle_indent(struct pretty_print_context *pp,
 {
 	strbuf_addchars(sb, ' ', indent);
 	if (pp->expand_tabs_in_log)
-		strbuf_add_tabexpand(sb, line, linelen);
+		strbuf_add_tabexpand(sb, pp->expand_tabs_in_log, line, linelen);
 	else
 		strbuf_add(sb, line, linelen);
 }
@@ -1723,7 +1723,8 @@ void pp_remainder(struct pretty_print_context *pp,
 		if (indent)
 			pp_handle_indent(pp, sb, indent, line, linelen);
 		else if (pp->expand_tabs_in_log)
-			strbuf_add_tabexpand(sb, line, linelen);
+			strbuf_add_tabexpand(sb, pp->expand_tabs_in_log,
+					     line, linelen);
 		else
 			strbuf_add(sb, line, linelen);
 		strbuf_addch(sb, '\n');
diff --git a/revision.c b/revision.c
index da53b6c..47e9ee7 100644
--- a/revision.c
+++ b/revision.c
@@ -1415,7 +1415,7 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	revs->expand_tabs_in_log = -1;
 
 	revs->commit_format = CMIT_FMT_DEFAULT;
-	revs->expand_tabs_in_log_default = 1;
+	revs->expand_tabs_in_log_default = 8;
 
 	init_grep_defaults();
 	grep_init(&revs->grep_filter, prefix);
@@ -1918,9 +1918,14 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->pretty_given = 1;
 		get_commit_format(arg+9, revs);
 	} else if (!strcmp(arg, "--expand-tabs")) {
-		revs->expand_tabs_in_log = 1;
+		revs->expand_tabs_in_log = 8;
 	} else if (!strcmp(arg, "--no-expand-tabs")) {
 		revs->expand_tabs_in_log = 0;
+	} else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
+		int val;
+		if (strtol_i(arg, 10, &val) < 0 || val < 0)
+			die("'%s': not a non-negative integer", arg);
+		revs->expand_tabs_in_log = val;
 	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;

diff --git a/t/t4213-log-tabexpand.sh b/t/t4213-log-tabexpand.sh
new file mode 100755
index 0000000..74ca03a
--- /dev/null
+++ b/t/t4213-log-tabexpand.sh
@@ -0,0 +1,98 @@
+#!/bin/sh
+
+test_description='log/show --expand-tabs'
+
+. ./test-lib.sh
+
+HT="	"
+title='tab indent at the beginning of the title line'
+body='tab indent on a line in the body'
+
+count_expand ()
+{
+	case " $* " in
+	*' --pretty=short '*)
+		line=$title ;;
+	*)
+		line=$body ;;
+	esac
+	expect=
+	count=$(( $1 + $2 )) ;# expected spaces
+	while test $count -gt 0
+	do
+		expect="$expect "
+		count=$(( $count - 1 ))
+	done
+	shift 2
+	count=$1 ;# expected tabs
+	while test $count -gt 0
+	do
+		expect="$expect$HT"
+		count=$(( $count - 1 ))
+	done
+	shift
+	{
+		echo "git show -s $*"
+		echo "$expect$line"
+	} | sed -e 's/ /./g' >expect
+
+	{
+		echo "git show -s $*"
+		git show -s "$@" |
+		sed -n -e "/$line\$/p"
+	} | sed -e 's/ /./g' >actual
+
+	test_cmp expect actual
+}
+
+test_expand ()
+{
+	fmt=$1
+	case "$fmt" in
+	*=raw | *=short | *=email)
+		default="0 1" ;;
+	*)
+		default="8 0" ;;
+	esac
+	case "$fmt" in
+	*=email)
+		in=0 ;;
+	*)
+		in=4 ;;
+	esac
+	test_expect_success "expand/no-expand${fmt:+ for $fmt}" '
+		count_expand $in $default $fmt &&
+		count_expand $in 8 0 $fmt --expand-tabs &&
+		count_expand $in 8 0 --expand-tabs $fmt &&
+		count_expand $in 8 0 $fmt --expand-tabs=8 &&
+		count_expand $in 8 0 --expand-tabs=8 $fmt &&
+		count_expand $in 0 1 $fmt --no-expand-tabs &&
+		count_expand $in 0 1 --no-expand-tabs $fmt &&
+		count_expand $in 0 1 $fmt --expand-tabs=0 &&
+		count_expand $in 0 1 --expand-tabs=0 $fmt &&
+		count_expand $in 4 0 $fmt --expand-tabs=4 &&
+		count_expand $in 4 0 --expand-tabs=4 $fmt
+	'
+}
+
+test_expect_success 'setup' '
+	test_tick &&
+	sed -e "s/Q/$HT/g" <<-EOF >msg &&
+	Q$title
+
+	Q$body
+	EOF
+	git commit --allow-empty -F msg
+'
+
+test_expand ""
+test_expand --pretty
+test_expand --pretty=short
+test_expand --pretty=medium
+test_expand --pretty=full
+test_expand --pretty=fuller
+test_expand --pretty=fuller
+test_expand --pretty=raw
+test_expand --pretty=email
+
+test_done

diff --git a/t/t4213-log-tabexpand.sh b/t/t4213-log-tabexpand.sh
new file mode 100755
index 0000000..e01a8f6
--- /dev/null
+++ b/t/t4213-log-tabexpand.sh
@@ -0,0 +1,105 @@
+#!/bin/sh
+
+test_description='log/show --expand-tabs'
+
+. ./test-lib.sh
+
+HT="	"
+title='tab indent at the beginning of the title line'
+body='tab indent on a line in the body'
+
+# usage: count_expand $indent $numSP $numHT @format_args
+count_expand ()
+{
+	expect=
+	count=$(( $1 + $2 )) ;# expected spaces
+	while test $count -gt 0
+	do
+		expect="$expect "
+		count=$(( $count - 1 ))
+	done
+	shift 2
+	count=$1 ;# expected tabs
+	while test $count -gt 0
+	do
+		expect="$expect$HT"
+		count=$(( $count - 1 ))
+	done
+	shift
+
+	# The remainder of the command line is "git show -s" options
+	case " $* " in
+	*' --pretty=short '*)
+		line=$title ;;
+	*)
+		line=$body ;;
+	esac
+
+	# Prefix the output with the command line arguments, and
+	# replace SP with a dot both in the expecte and actual output
+	# so that test_cmp would show the differene together with the
+	# breakage in a way easier to consume by the debugging user.
+	{
+		echo "git show -s $*"
+		echo "$expect$line"
+	} | sed -e 's/ /./g' >expect
+
+	{
+		echo "git show -s $*"
+		git show -s "$@" |
+		sed -n -e "/$line\$/p"
+	} | sed -e 's/ /./g' >actual
+
+	test_cmp expect actual
+}
+
+test_expand ()
+{
+	fmt=$1
+	case "$fmt" in
+	*=raw | *=short | *=email)
+		default="0 1" ;;
+	*)
+		default="8 0" ;;
+	esac
+	case "$fmt" in
+	*=email)
+		in=0 ;;
+	*)
+		in=4 ;;
+	esac
+	test_expect_success "expand/no-expand${fmt:+ for $fmt}" '
+		count_expand $in $default $fmt &&
+		count_expand $in 8 0 $fmt --expand-tabs &&
+		count_expand $in 8 0 --expand-tabs $fmt &&
+		count_expand $in 8 0 $fmt --expand-tabs=8 &&
+		count_expand $in 8 0 --expand-tabs=8 $fmt &&
+		count_expand $in 0 1 $fmt --no-expand-tabs &&
+		count_expand $in 0 1 --no-expand-tabs $fmt &&
+		count_expand $in 0 1 $fmt --expand-tabs=0 &&
+		count_expand $in 0 1 --expand-tabs=0 $fmt &&
+		count_expand $in 4 0 $fmt --expand-tabs=4 &&
+		count_expand $in 4 0 --expand-tabs=4 $fmt
+	'
+}
+
+test_expect_success 'setup' '
+	test_tick &&
+	sed -e "s/Q/$HT/g" <<-EOF >msg &&
+	Q$title
+
+	Q$body
+	EOF
+	git commit --allow-empty -F msg
+'
+
+test_expand ""
+test_expand --pretty
+test_expand --pretty=short
+test_expand --pretty=medium
+test_expand --pretty=full
+test_expand --pretty=fuller
+test_expand --pretty=raw
+test_expand --pretty=email
+
+test_done

diff --git a/pretty.c b/pretty.c
index 0b40457f99f0..b9374a1708d1 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1699,6 +1699,18 @@ static int pp_handle_indent(struct strbuf *sb, int indent,
 	return 1;
 }
 
+static void pp_add_line(struct pretty_print_context *pp,
+			struct strbuf *sb, int indent,
+			const char *line, int linelen)
+{
+	strbuf_grow(sb, linelen + indent + 20);
+	if (indent) {
+		if (pp_handle_indent(sb, indent, line, linelen))
+			return;
+	}
+	strbuf_add(sb, line, linelen);
+}
+
 void pp_remainder(struct pretty_print_context *pp,
 		  const char **msg_p,
 		  struct strbuf *sb,
@@ -1721,12 +1733,7 @@ void pp_remainder(struct pretty_print_context *pp,
 		}
 		first = 0;
 
-		strbuf_grow(sb, linelen + indent + 20);
-		if (indent) {
-			if (pp_handle_indent(sb, indent, line, linelen))
-				linelen = 0;
-		}
-		strbuf_add(sb, line, linelen);
+		pp_add_line(pp, sb, indent, line, linelen);
 		strbuf_addch(sb, '\n');
 	}
 }