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[PATCH 4/9] interpret-trailers: tighten check for "---" patch boundary

From
Jeff King <peff@peff.net>
Date
Aug 23, 2018, 00:48 UTC
Message-ID
<20180823004821.GD3126@sigill.intra.peff.net>
In-Reply-To
<20180823004300.GA1355@sigill.intra.peff.net>

The interpret-trailers command accepts not only raw commit messages, but it also can manipulate trailers in format-patch output. That means it must find the "---" boundary separating the commit message from the patch. However, it does so by looking for any line starting with "---", regardless of whether there is further content.

This is overly lax compared to the parsing done in mailinfo.c's patchbreak(), and may cause false positives (e.g., t/perf output tables uses dashes; if you cut and paste them into your commit message, it fools the parser).

We could try to reuse patchbreak() here, but it actually has several heuristics that are not of interest to us (e.g., matching "diff -" without a three-dash separator or even a CVS "Index:" line). We're not interested in taking in whatever random cruft people may send, but rather handling git-formatted patches.

Note that the existing documentation was written in a loose way, so technically we are changing the behavior from what it said. But this should implement the original intent in a more accurate way.

Signed-off-by: Jeff King <peff@peff.net>
---
By itself, this would fix the case that spawned this
discussion, though we still have false positives on "---" in
a commit message.
 Documentation/git-interpret-trailers.txt |  5 +++--
 t/t7513-interpret-trailers.sh            | 22 ++++++++++++++++++++++
 trailer.c                                |  4 +++-
 3 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/Documentation/git-interpret-trailers.txt b/Documentation/git-interpret-trailers.txt
index b8fafb1e8b..7385bfdb45 100644
--- a/Documentation/git-interpret-trailers.txt
+++ b/Documentation/git-interpret-trailers.txt
@@ -56,8 +56,9 @@ least one Git-generated or user-configured trailer and consists of at
 least 25% trailers.
 The group must be preceded by one or more empty (or whitespace-only) lines.
 The group must either be at the end of the message or be the last
-non-whitespace lines before a line that starts with '---'. Such three
-minus signs start the patch part of the message.
+non-whitespace lines before a line that starts with '---' (followed by a
+space or the end of the line). Such three minus signs start the patch
+part of the message.
 
 When reading trailers, there can be whitespaces after the
 token, the separator and the value. There can also be whitespaces
diff --git a/t/t7513-interpret-trailers.sh b/t/t7513-interpret-trailers.sh
index 164719d1c9..e13b40b43f 100755
--- a/t/t7513-interpret-trailers.sh
+++ b/t/t7513-interpret-trailers.sh
@@ -1417,4 +1417,26 @@ test_expect_success 'unfold' '
 	test_cmp expected actual
 '
 
+test_expect_success 'handling of --- lines in input' '
+	echo "real-trailer: just right" >expected &&
+
+	git interpret-trailers --parse >actual <<-\EOF &&
+	subject
+
+	body
+
+	not-a-trailer: too soon
+	------ this is just a line in the commit message with a bunch of
+	------ dashes; it does not have any syntactic meaning.
+
+	real-trailer: just right
+	---
+	below the dashed line may be a patch, etc.
+
+	not-a-trailer: too late
+	EOF
+
+	test_cmp expected actual
+'
+
 test_done
diff --git a/trailer.c b/trailer.c
index e769c5b72c..8392c6c030 100644
--- a/trailer.c
+++ b/trailer.c
@@ -793,7 +793,9 @@ static size_t find_patch_start(const char *str)
 	const char *s;
 
 	for (s = str; *s; s = next_line(s)) {
-		if (starts_with(s, "---"))
+		const char *v;
+
+		if (skip_prefix(s, "---", &v) && isspace(*v))
 			return s - str;
 	}
 
-- 
2.19.0.rc0.412.g7005db4e88
Previous: Jeff KingNext: Jeff King
Message 45 of 53 in “test-tool.h: include git-compat-util.h”
  1. test-tool.h: include git-compat-util.hJeff King, Aug 21, 2018
  2. Junio C HamanoAug 21, 2018
  3. 1/6 t/perf: factor boilerplate out of test_perfJeff King, Aug 21, 2018
  4. 2/6 t/perf: factor out percent calculationsJeff King, Aug 21, 2018
  5. 3/6 t/perf: add infrastructure for measuring sizesJeff King, Aug 21, 2018
  6. Derrick StoleeAug 22, 2018
  7. Jeff KingAug 22, 2018
  8. 4/6 t/perf: add perf tests for fetches from a bitmapped serverJeff King, Aug 21, 2018
  9. 5/6 pack-bitmap: save "have" bitmap from walkJeff King, Aug 21, 2018
  10. Derrick StoleeAug 21, 2018
  11. Jeff KingAug 21, 2018
  12. Ævar Arnfjörð BjarmasonAug 31, 2018
  13. Jeff KingAug 31, 2018
  14. 0/4 un-breaking pack-objects with bitmapsJeff King, Sep 1, 2018
  15. 1/4 bitmap_has_sha1_in_uninteresting(): drop BUG checkJeff King, Sep 1, 2018
  16. 2/4 t5310: test delta reuse with bitmapsJeff King, Sep 1, 2018
  17. Jeff KingSep 1, 2018
  18. Ævar Arnfjörð BjarmasonSep 1, 2018
  19. Ben PeartSep 1, 2018
  20. Jeff KingSep 2, 2018
  21. Stefan BellerSep 4, 2018
  22. Junio C HamanoSep 4, 2018
  23. Jeff KingSep 4, 2018
  24. 3/4 traverse_bitmap_commit_list(): don't free resultJeff King, Sep 1, 2018
  25. 4/4 pack-bitmap: drop "loaded" flagJeff King, Sep 1, 2018
  26. Stefan BellerSep 4, 2018
  27. Jeff KingSep 4, 2018
  28. Ævar Arnfjörð BjarmasonSep 8, 2018
  29. Junio C HamanoSep 10, 2018
  30. Jeff KingSep 10, 2018
  31. Junio C HamanoSep 10, 2018
  32. 6/6 pack-objects: reuse on-disk deltas for thin "have" objectsJeff King, Aug 21, 2018
  33. Junio C HamanoAug 21, 2018
  34. Junio C HamanoAug 21, 2018
  35. Jeff KingAug 21, 2018
  36. Jeff KingAug 21, 2018
  37. Junio C HamanoAug 21, 2018
  38. Jeff KingAug 21, 2018
  39. Junio C HamanoAug 21, 2018
  40. Jeff KingAug 21, 2018
  41. 0/9 trailer-parsing false positivesJeff King, Aug 23, 2018
  42. 1/9 trailer: use size_t for string offsetsJeff King, Aug 23, 2018
  43. 2/9 trailer: use size_t for iterating trailer listJeff King, Aug 23, 2018
  44. 3/9 trailer: pass process_trailer_opts to trailer_info_get()Jeff King, Aug 23, 2018
  45. 4/9 interpret-trailers: tighten check for "---" patch boundaryJeff King, Aug 23, 2018
  46. 5/9 interpret-trailers: allow suppressing "---" dividerJeff King, Aug 23, 2018
  47. 6/9 pretty, ref-filter: format %(trailers) with no_divider optionJeff King, Aug 23, 2018
  48. 7/9 sequencer: ignore "---" divider when parsing trailersJeff King, Aug 23, 2018
  49. 8/9 append_signoff: use size_t for string offsetsJeff King, Aug 23, 2018
  50. 9/9 sequencer: handle ignore_footer when parsing trailersJeff King, Aug 23, 2018
  51. Junio C HamanoAug 23, 2018
  52. Jeff KingAug 24, 2018
  53. Jeff KingAug 21, 2018

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