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[PATCH 06/14] format-patch: allow --interdiff to apply to a lone-patch

From
Eric Sunshine <sunshine@sunshineco.com>
Date
Jul 22, 2018, 09:57 UTC
Message-ID
<20180722095717.17912-7-sunshine@sunshineco.com>
In-Reply-To
<20180722095717.17912-1-sunshine@sunshineco.com>

When submitting a revised version of a patch or series, it can be helpful (to reviewers) to include a summary of changes since the previous attempt in the form of an interdiff, typically in the cover letter. However, it is occasionally useful, despite making for a noisy read, to insert an interdiff into the commentary section of the lone patch of a 1-patch series.

Therefore, extend "git format-patch --interdiff=<prev>" to insert an interdiff into the commentary section of a lone patch rather than requiring a cover letter. The interdiff is indented to avoid confusing git-am and human readers into considering it part of the patch proper.

Implementation note: Generating an interdiff for insertion into the commentary section of a patch which itself is currently being generated requires invoking the diffing machinery recursively. However, the machinery does not (presently) support this since it uses global state. Consequently, we need to take care to stash away the state of the in-progress operation while generating the interdiff, and restore it after.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
---
 Documentation/git-format-patch.txt |  3 ++-
 builtin/log.c                      |  8 +++++---
 log-tree.c                         | 14 ++++++++++++++
 t/t4014-format-patch.sh            | 12 ++++++++++++
 4 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index a1b1bafee7..f8a061794d 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -230,7 +230,8 @@ feeding the result to `git send-email`.
 	fill in a description in the file before sending it out.
 
 --interdiff=<previous>::
-	As a reviewer aid, insert an interdiff into the cover letter showing
+	As a reviewer aid, insert an interdiff into the cover letter,
+	or as commentary of the lone patch of a 1-patch series, showing
 	the differences between the previous version of the patch series and
 	the series currently being formatted. `previous` is a single revision
 	naming the tip of the previous series which shares a common base with
diff --git a/builtin/log.c b/builtin/log.c
index 8078a43d14..e990027c28 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1540,7 +1540,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "progress", &show_progress,
 			 N_("show progress while generating patches")),
 		OPT_CALLBACK(0, "interdiff", &idiff_prev, N_("rev"),
-			     N_("show changes against <rev> in cover letter"),
+			     N_("show changes against <rev> in cover letter or single patch"),
 			     parse_opt_object_name),
 		OPT_END()
 	};
@@ -1765,8 +1765,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		rev.total = total + start_number - 1;
 
 	if (idiff_prev.nr) {
-		if (!cover_letter)
-			die(_("--interdiff requires --cover-letter"));
+		if (!cover_letter && total != 1)
+			die(_("--interdiff requires --cover-letter or single patch"));
 		rev.idiff_oid1 = &idiff_prev.oid[idiff_prev.nr - 1];
 		rev.idiff_oid2 = get_commit_tree_oid(list[0]);
 		rev.idiff_title = diff_title(&idiff_title, reroll_count,
@@ -1811,6 +1811,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		print_signature(rev.diffopt.file);
 		total++;
 		start_number--;
+		/* interdiff in cover-letter; omit from patches */
+		rev.idiff_oid1 = NULL;
 	}
 	rev.add_signoff = do_signoff;
 
diff --git a/log-tree.c b/log-tree.c
index 9d38f1cf79..56513fa83d 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -14,6 +14,7 @@
 #include "sequencer.h"
 #include "line-log.h"
 #include "help.h"
+#include "interdiff.h"
 
 static struct decoration name_decoration = { "object names" };
 static int decoration_loaded;
@@ -736,6 +737,19 @@ void show_log(struct rev_info *opt)
 
 	strbuf_release(&msgbuf);
 	free(ctx.notes_message);
+
+	if (cmit_fmt_is_mail(ctx.fmt) && opt->idiff_oid1) {
+		struct diff_queue_struct dq;
+
+		memcpy(&dq, &diff_queued_diff, sizeof(diff_queued_diff));
+		DIFF_QUEUE_CLEAR(&diff_queued_diff);
+
+		next_commentary_block(opt, NULL);
+		fprintf_ln(opt->diffopt.file, "%s", opt->idiff_title);
+		show_interdiff(opt, 2);
+
+		memcpy(&diff_queued_diff, &dq, sizeof(diff_queued_diff));
+	}
 }
 
 int log_tree_diff_flush(struct rev_info *opt)
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index 5950890d30..909c743c13 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -1730,6 +1730,7 @@ test_expect_success 'interdiff: cover-letter' '
 	EOF
 	git format-patch --cover-letter --interdiff=boop~2 -1 boop &&
 	test_i18ngrep "^Interdiff:$" 0000-cover-letter.patch &&
+	test_i18ngrep ! "^Interdiff:$" 0001-fleep.patch &&
 	sed "1,/^@@ /d; /^-- $/q" <0000-cover-letter.patch >actual &&
 	test_cmp expect actual
 '
@@ -1739,4 +1740,15 @@ test_expect_success 'interdiff: reroll-count' '
 	test_i18ngrep "^Interdiff ..* v1:$" v2-0000-cover-letter.patch
 '
 
+test_expect_success 'interdiff: solo-patch' '
+	cat >expect <<-\EOF &&
+	  +fleep
+
+	EOF
+	git format-patch --interdiff=boop~2 -1 boop &&
+	test_i18ngrep "^Interdiff:$" 0001-fleep.patch &&
+	sed "1,/^  @@ /d; /^$/q" <0001-fleep.patch >actual &&
+	test_cmp expect actual
+'
+
 test_done
-- 
2.18.0.345.g5c9ce644c3
Previous: Eric SunshineNext: Duy Nguyen
Message 13 of 38 in “format-patch: add --interdiff and --range-diff options”
  1. 00/14 format-patch: add --interdiff and --range-diff optionsEric Sunshine, Jul 22, 2018
  2. 01/14 format-patch: allow additional generated content in make_cover_letter()Eric Sunshine, Jul 22, 2018
  3. 02/14 format-patch: add --interdiff option to embed diff in cover letterEric Sunshine, Jul 22, 2018
  4. Eric SunshineJul 22, 2018
  5. Duy NguyenJul 23, 2018
  6. Eric SunshineJul 23, 2018
  7. Junio C HamanoJul 23, 2018
  8. 03/14 format-patch: teach --interdiff to respect -v/--reroll-countEric Sunshine, Jul 22, 2018
  9. Duy NguyenJul 23, 2018
  10. Eric SunshineJul 23, 2018
  11. 04/14 interdiff: teach show_interdiff() to indent interdiffEric Sunshine, Jul 22, 2018
  12. 05/14 log-tree: show_log: make commentary block delimiting reusableEric Sunshine, Jul 22, 2018
  13. 06/14 format-patch: allow --interdiff to apply to a lone-patchEric Sunshine, Jul 22, 2018
  14. Duy NguyenJul 23, 2018
  15. Eric SunshineJul 23, 2018
  16. 08/14 range-diff: publish default creation factorEric Sunshine, Jul 22, 2018
  17. 09/14 range-diff: relieve callers of low-level configuration burdenEric Sunshine, Jul 22, 2018
  18. 10/14 format-patch: add --range-diff option to embed diff in cover letterEric Sunshine, Jul 22, 2018
  19. Duy NguyenJul 23, 2018
  20. Eric SunshineJul 23, 2018
  21. Junio C HamanoJul 25, 2018
  22. Eric SunshineJul 25, 2018
  23. Junio C HamanoJul 25, 2018
  24. Duy NguyenJul 25, 2018
  25. 07/14 range-diff: respect diff_option.file rather than assuming 'stdout'Eric Sunshine, Jul 22, 2018
  26. Stefan BellerJul 23, 2018
  27. Eric SunshineJul 23, 2018
  28. Junio C HamanoJul 25, 2018
  29. 12/14 format-patch: teach --range-diff to respect -v/--reroll-countEric Sunshine, Jul 22, 2018
  30. 14/14 format-patch: allow --range-diff to apply to a lone-patchEric Sunshine, Jul 22, 2018
  31. Junio C HamanoJul 25, 2018
  32. Eric SunshineSep 7, 2018
  33. 13/14 format-patch: add --creation-factor tweak for --range-diffEric Sunshine, Jul 22, 2018
  34. 11/14 format-patch: extend --range-diff to accept revision rangeEric Sunshine, Jul 22, 2018
  35. Junio C HamanoJul 25, 2018
  36. Eric SunshineSep 7, 2018
  37. Duy NguyenJul 23, 2018
  38. Eric SunshineJul 23, 2018

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