[PATCH v3 0/2] Make find_commit_subject() consistent with --format=%s

[Johannes Schindelin <johannes.schindelin@gmx.de>]

In an intermediate iteration of my rebase--helper patches, I
accidentally generated commits with more than one empty line
between the header and the commit message. When using
find_commit_subject() to show the oneline, it turned up empty, even
if the output of `git show --format=%s` looked fine.

Turned out that the pretty-printing machinery helpfully skipped any
blank lines before the commit message.

In the first iteration of this patch, I failed to notice that
the skip_empty_lines() function used by the pretty printing (which is
declared static, and therefore I originally did not use it in order to
keep the patch as minimal as possible) skips also blank lines.

To make things truly consistent, I now just make the skip_empty_lines()
function public, and then use it.


Johannes Schindelin (2):
  Make the skip_empty_lines() function public
  Make find_commit_subject() more robust

 commit.c                 |  2 +-
 commit.h                 |  1 +
 pretty.c                 |  2 +-
 t/t8008-blame-formats.sh | 17 +++++++++++++++++
 4 files changed, 20 insertions(+), 2 deletions(-)

Published-As: https://github.com/dscho/git/releases/tag/leading-empty-lines-v3
Interdiff vs v2:

 diff --git a/commit.c b/commit.c
 index 7b00989..0bf868f 100644
 --- a/commit.c
 +++ b/commit.c
 @@ -414,9 +414,7 @@ int find_commit_subject(const char *commit_buffer, const char **subject)
  	while (*p && (*p != '\n' || p[1] != '\n'))
  		p++;
  	if (*p) {
 -		p += 2;
 -		while (*p == '\n')
 -			p++;
 +		p = skip_empty_lines(p + 2);
  		for (eol = p; *eol && *eol != '\n'; eol++)
  			; /* do nothing */
  	} else
 diff --git a/commit.h b/commit.h
 index b06db4d..fbdd18d 100644
 --- a/commit.h
 +++ b/commit.h
 @@ -177,6 +177,7 @@ extern const char *format_subject(struct strbuf *sb, const char *msg,
  				  const char *line_separator);
  extern void userformat_find_requirements(const char *fmt, struct userformat_want *w);
  extern int commit_format_is_empty(enum cmit_fmt);
 +extern const char *skip_empty_lines(const char *msg);
  extern void format_commit_message(const struct commit *commit,
  				  const char *format, struct strbuf *sb,
  				  const struct pretty_print_context *context);
 diff --git a/pretty.c b/pretty.c
 index c3ec430..1b807b4 100644
 --- a/pretty.c
 +++ b/pretty.c
 @@ -516,7 +516,7 @@ static int is_empty_line(const char *line, int *len_p)
  	return !len;
  }
  
 -static const char *skip_empty_lines(const char *msg)
 +const char *skip_empty_lines(const char *msg)
  {
  	for (;;) {
  		int linelen = get_one_line(msg);
 diff --git a/t/t8008-blame-formats.sh b/t/t8008-blame-formats.sh
 index 03bd313..b98f9a4 100755
 --- a/t/t8008-blame-formats.sh
 +++ b/t/t8008-blame-formats.sh
 @@ -94,7 +94,7 @@ test_expect_success '--porcelain detects first non-empty line as subject' '
  		echo "This is it" >single-file &&
  		git add single-file &&
  		tree=$(git write-tree) &&
 -		commit=$(printf "%s\n%s\n%s\n\n\noneline\n\nbody\n" \
 +		commit=$(printf "%s\n%s\n%s\n\n\n  \noneline\n\nbody\n" \
  			"tree $tree" \
  			"author A <a@b.c> 123456789 +0000" \
  			"committer C <c@d.e> 123456789 +0000" |

-- 
2.9.0.118.g0e1a633

base-commit: ab7797dbe95fff38d9265869ea367020046db118