Show changes to 6 files +126 −18
Documentation/diff-options.txt, cache.h, diff.c, diff.h, t/t4063-diff-expand-tabs.sh, ws.c
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 89cc0f48deef..82e314b20b3d 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -329,6 +329,12 @@ endif::git-format-patch[]
the diff-patch output format. Non default number of
digits can be specified with `--abbrev=<n>`.
+--diff-expand-tabs[=<n>]::
+ When showing diff output, expand any tabs into spaces first before
+ printing. The size of the tabs is determined by <n> which defaults to
+ 8 if not provided. --no-diff-expand-tabs or a size of 0 will disable
+ expansion.
+
-B[<n>][/<m>]::
--break-rewrites[=[<n>][/<m>]]::
Break complete rewrite changes into pairs of delete and
diff --git a/cache.h b/cache.h
index 5c8078291c47..2e221174edd4 100644
--- a/cache.h
+++ b/cache.h
@@ -2155,7 +2155,7 @@ extern unsigned whitespace_rule_cfg;
extern unsigned whitespace_rule(const char *);
extern unsigned parse_whitespace_rule(const char *);
extern unsigned ws_check(const char *line, int len, unsigned ws_rule);
-extern void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws);
+extern void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws, int expand_tabs);
extern char *whitespace_error_string(unsigned ws);
extern void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
extern int ws_blank_line(const char *line, int len, unsigned ws_rule);
diff --git a/diff.c b/diff.c
index 58cb72d7e72a..488019335df7 100644
--- a/diff.c
+++ b/diff.c
@@ -544,7 +544,14 @@ static void emit_line_0(struct diff_options *o, const char *set, const char *res
fputs(set, file);
if (!nofirst)
fputc(first, file);
- fwrite(line, len, 1, file);
+ if (o->expand_tabs) {
+ struct strbuf sb = STRBUF_INIT;
+ strbuf_add_tabexpand(&sb, o->expand_tabs, line, len);
+ fwrite(sb.buf, sb.len, 1, file);
+ strbuf_release(&sb);
+ } else {
+ fwrite(line, len, 1, file);
+ }
fputs(reset, file);
}
if (has_trailing_carriage_return)
@@ -595,7 +602,8 @@ static void emit_line_checked(const char *reset,
/* Emit just the prefix, then the rest. */
emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
ws_check_emit(line, len, ecbdata->ws_rule,
- ecbdata->opt->file, set, reset, ws);
+ ecbdata->opt->file, set, reset, ws,
+ ecbdata->opt->expand_tabs);
}
}
@@ -2190,7 +2198,7 @@ static void checkdiff_consume(void *priv, char *line, unsigned long len)
free(err);
emit_line(data->o, set, reset, line, 1);
ws_check_emit(line + 1, len - 1, data->ws_rule,
- data->o->file, set, reset, ws);
+ data->o->file, set, reset, ws, 0);
} else if (line[0] == ' ') {
data->lineno++;
} else if (line[0] == '@') {
@@ -4044,6 +4052,15 @@ int diff_opt_parse(struct diff_options *options,
else if (40 < options->abbrev)
options->abbrev = 40;
}
+ else if (!strcmp(arg, "--no-diff-expand-tabs"))
+ options->expand_tabs = 0;
+ else if (!strcmp(arg, "--diff-expand-tabs"))
+ options->expand_tabs = DEFAULT_EXPAND_TAB_WIDTH;
+ else if (skip_prefix(arg, "--diff-expand-tabs=", &arg)) {
+ options->expand_tabs = strtoul(arg, NULL, 10);
+ if (options->expand_tabs < 0)
+ options->expand_tabs = 0;
+ }
else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
options->a_prefix = optarg;
return argcount;
diff --git a/diff.h b/diff.h
index e9ccb38c26c7..3de7fe68e6b1 100644
--- a/diff.h
+++ b/diff.h
@@ -147,6 +147,8 @@ struct diff_options {
int setup;
int abbrev;
int ita_invisible_in_index;
+#define DEFAULT_EXPAND_TAB_WIDTH 8
+ int expand_tabs;
/* white-space error highlighting */
#define WSEH_NEW 1
#define WSEH_CONTEXT 2
@@ -308,6 +310,10 @@ extern void diffcore_fix_diff_index(struct diff_options *);
" --name-status show names and status of changed files.\n" \
" --full-index show full object name on index lines.\n" \
" --abbrev=<n> abbreviate object names in diff-tree header and diff-raw.\n" \
+" --diff-expand-tabs=<n>\n" \
+" expand tabs in the output to spaces, to preserve the\n" \
+" alignment of tabs as compared to the input. Tabs will expand\n" \
+" to <n> spaces. If <n> is 0, expansion is disabled.\n" \
" -R swap input file pairs.\n" \
" -B detect complete rewrites.\n" \
" -M detect renames.\n" \
diff --git a/t/t4063-diff-expand-tabs.sh b/t/t4063-diff-expand-tabs.sh
new file mode 100755
index 000000000000..929a6103f6aa
--- /dev/null
+++ b/t/t4063-diff-expand-tabs.sh
@@ -0,0 +1,65 @@
+#!/bin/sh
+#
+# Copyright (c) 2017 Jacob Keller
+#
+
+test_description='Test diff tab expansion
+
+'
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/diff-lib.sh
+
+test_expect_success '--diff-expand-tabs setup' '
+ git reset --hard &&
+ {
+ echo "0. no tabs"
+ } >x &&
+ git update-index --add x &&
+ git commit -a --allow-empty -m preimage &&
+ {
+ echo "0. some tabs"
+ } >x &&
+
+ cat >expect.default <<-\EOF &&
+ diff --git a/x b/x
+ index e4d15da..410478b 100644
+ --- a/x
+ +++ b/x
+ @@ -1 +1 @@
+ -0. no tabs
+ +0. some tabs
+ EOF
+
+ cat >expect.size-12 <<-\EOF &&
+ diff --git a/x b/x
+ index e4d15da..410478b 100644
+ --- a/x
+ +++ b/x
+ @@ -1 +1 @@
+ -0. no tabs
+ +0. some tabs
+ EOF
+
+ cat >expect.size-0 <<-\EOF
+ diff --git a/x b/x
+ index e4d15da..410478b 100644
+ --- a/x
+ +++ b/x
+ @@ -1 +1 @@
+ -0. no tabs
+ +0. some tabs
+ EOF
+'
+
+test_expect_success 'test --diff-expand-tabs option' '
+ git diff --diff-expand-tabs >actual &&
+ test_cmp expect.default actual &&
+
+ git diff --diff-expand-tabs=12 >actual &&
+ test_cmp expect.size-12 actual &&
+
+ git diff --diff-expand-tabs=0 >actual &&
+ test_cmp expect.size-0 actual
+'
+
+test_done
diff --git a/ws.c b/ws.c
index a07caedd5a56..316081c7c2ee 100644
--- a/ws.c
+++ b/ws.c
@@ -139,10 +139,24 @@ char *whitespace_error_string(unsigned ws)
return strbuf_detach(&err, NULL);
}
+/* Emit the line to the stream, expanding tabs if necessary */
+static void ws_emit(int expand_tabs, const char *line, int len, FILE *stream)
+{
+ if (expand_tabs) {
+ struct strbuf sb = STRBUF_INIT;
+ strbuf_add_tabexpand(&sb, expand_tabs, line, len);
+ fwrite(sb.buf, sb.len, 1, stream);
+ strbuf_release(&sb);
+ } else {
+ fwrite(line, len, 1, stream);
+ }
+}
+
/* If stream is non-NULL, emits the line after checking. */
static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
FILE *stream, const char *set,
- const char *reset, const char *ws)
+ const char *reset, const char *ws,
+ int expand_tabs)
{
unsigned result = 0;
int written = 0;
@@ -187,20 +201,20 @@ static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
result |= WS_SPACE_BEFORE_TAB;
if (stream) {
fputs(ws, stream);
- fwrite(line + written, i - written, 1, stream);
+ ws_emit(expand_tabs, line + written, i - written, stream);
fputs(reset, stream);
- fwrite(line + i, 1, 1, stream);
+ ws_emit(expand_tabs, line + i, 1, stream);
}
} else if (ws_rule & WS_TAB_IN_INDENT) {
result |= WS_TAB_IN_INDENT;
if (stream) {
- fwrite(line + written, i - written, 1, stream);
+ ws_emit(expand_tabs, line + written, i - written, stream);
fputs(ws, stream);
- fwrite(line + i, 1, 1, stream);
+ ws_emit(expand_tabs, line + i, 1, stream);
fputs(reset, stream);
}
} else if (stream) {
- fwrite(line + written, i - written + 1, 1, stream);
+ ws_emit(expand_tabs, line + written, i - written + 1, stream);
}
written = i + 1;
}
@@ -210,7 +224,7 @@ static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
result |= WS_INDENT_WITH_NON_TAB;
if (stream) {
fputs(ws, stream);
- fwrite(line + written, i - written, 1, stream);
+ ws_emit(expand_tabs, line + written, i - written, stream);
fputs(reset, stream);
}
written = i;
@@ -225,16 +239,16 @@ static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
/* Emit non-highlighted (middle) segment. */
if (trailing_whitespace - written > 0) {
fputs(set, stream);
- fwrite(line + written,
- trailing_whitespace - written, 1, stream);
+ ws_emit(expand_tabs, line + written,
+ trailing_whitespace - written, stream);
fputs(reset, stream);
}
/* Highlight errors in trailing whitespace. */
if (trailing_whitespace != len) {
fputs(ws, stream);
- fwrite(line + trailing_whitespace,
- len - trailing_whitespace, 1, stream);
+ ws_emit(expand_tabs, line + trailing_whitespace,
+ len - trailing_whitespace, stream);
fputs(reset, stream);
}
if (trailing_carriage_return)
@@ -247,14 +261,14 @@ static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
void ws_check_emit(const char *line, int len, unsigned ws_rule,
FILE *stream, const char *set,
- const char *reset, const char *ws)
+ const char *reset, const char *ws, int expand_tabs)
{
- (void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
+ (void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws, expand_tabs);
}
unsigned ws_check(const char *line, int len, unsigned ws_rule)
{
- return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
+ return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL, 0);
}
int ws_blank_line(const char *line, int len, unsigned ws_rule)
Jacob Keller
