commit: allow core.commentChar=auto for character auto selection

When core.commentChar is "auto", the comment char starts with '#' as
in default but if it's already in the prepared message, find another
char in a small subset. This should stop surprises because git strips
some lines unexpectedly.

Note that git is not smart enough to recognize '#' as the comment char
in custom templates and convert it if the final comment char is
different. It thinks '#' lines in custom templates as part of the
commit message. So don't use this with custom templates.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 1932e9b9a2be5437dd467f91472318a5bf1bb992..9f3ce06c8734d2fca2752b28192aea9f8a19cf58 100644 (file)
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -544,6 +544,9 @@ core.commentchar::
        messages consider a line that begins with this character
        commented, and removes them after the editor returns
        (default '#').
++
+If set to "auto", `git-commit` would select a character that is not
+the beginning character of any line in existing commit messages.
 
 sequence.editor::
        Text editor used by `git rebase -i` for editing the rebase instruction file.

diff --git a/builtin/commit.c b/builtin/commit.c
index 9cfef6c6cca61973a4982763e4b834bf1b45cb75..515c4c4c0553c00c0ad6d577af192a96cf1bc60a 100644 (file)
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -594,6 +594,36 @@ static char *cut_ident_timestamp_part(char *string)
        return ket;
 }
 
+static void adjust_comment_line_char(const struct strbuf *sb)
+{
+       char candidates[] = "#;@!$%^&|:";
+       char *candidate;
+       const char *p;
+
+       comment_line_char = candidates[0];
+       if (!memchr(sb->buf, comment_line_char, sb->len))
+               return;
+
+       p = sb->buf;
+       candidate = strchr(candidates, *p);
+       if (candidate)
+               *candidate = ' ';
+       for (p = sb->buf; *p; p++) {
+               if ((p[0] == '\n' || p[0] == '\r') && p[1]) {
+                       candidate = strchr(candidates, p[1]);
+                       if (candidate)
+                               *candidate = ' ';
+               }
+       }
+
+       for (p = candidates; *p == ' '; p++)
+               ;
+       if (!*p)
+               die(_("unable to select a comment character that is not used\n"
+                     "in the current commit message"));
+       comment_line_char = *p;
+}
+
 static int prepare_to_commit(const char *index_file, const char *prefix,
                             struct commit *current_head,
                             struct wt_status *s,
@@ -748,6 +778,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
        if (fwrite(sb.buf, 1, sb.len, s->fp) < sb.len)
                die_errno(_("could not write commit template"));
 
+       if (auto_comment_line_char)
+               adjust_comment_line_char(&sb);
        strbuf_release(&sb);
 
        /* This checks if committer ident is explicitly given */

diff --git a/cache.h b/cache.h
index 107ac61b68f15b1e15532c09fda9e9799f830e44..646fb810bb38f5a942fab7bb091e1d965443d1b8 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -602,6 +602,7 @@ extern int precomposed_unicode;
  * that is subject to stripspace.
  */
 extern char comment_line_char;
+extern int auto_comment_line_char;
 
 enum branch_track {
        BRANCH_TRACK_UNSPECIFIED = -1,

diff --git a/config.c b/config.c
index 491a9050aebdeff2ca081cf6d6652188c0a77e1d..d29c733419829295961898f754271871f807a505 100644 (file)
--- a/config.c
+++ b/config.c
@@ -828,8 +828,11 @@ static int git_default_core_config(const char *var, const char *value)
                int ret = git_config_string(&comment, var, value);
                if (ret)
                        return ret;
+               else if (!strcasecmp(comment, "auto"))
+                       auto_comment_line_char = 1;
                else if (comment[0] && !comment[1]) {
                        comment_line_char = comment[0];
+                       auto_comment_line_char = 0;
                } else
                        return error("core.commentChar should only be one character");
                return 0;

diff --git a/environment.c b/environment.c
index 5c4815dbe132fc358aa55eeb20d86d867c97c37f..f2de1ee9ada0c1211fe7e31da52011ec0825758d 100644 (file)
--- a/environment.c
+++ b/environment.c
@@ -69,6 +69,7 @@ unsigned long pack_size_limit_cfg;
  * that is subject to stripspace.
  */
 char comment_line_char = '#';
+int auto_comment_line_char;
 
 /* Parallel index stat data preload? */
 int core_preload_index = 0;

diff --git a/t/t7502-commit.sh b/t/t7502-commit.sh
index 9a3f3a1b4151ebf16cfd773a0f9efcb1b61d40d7..30e46884f29722c38b8fd664339b8440a2b042e4 100755 (executable)
--- a/t/t7502-commit.sh
+++ b/t/t7502-commit.sh
@@ -563,4 +563,30 @@ test_expect_success 'commit --status with custom comment character' '
        test_i18ngrep "^; Changes to be committed:" .git/COMMIT_EDITMSG
 '
 
+test_expect_success 'switch core.commentchar' '
+       test_commit "#foo" foo &&
+       GIT_EDITOR=.git/FAKE_EDITOR git -c core.commentChar=auto commit --amend &&
+       test_i18ngrep "^; Changes to be committed:" .git/COMMIT_EDITMSG
+'
+
+test_expect_success 'switch core.commentchar but out of options' '
+       cat >text <<\EOF &&
+# 1
+; 2
+@ 3
+! 4
+$ 5
+% 6
+^ 7
+& 8
+| 9
+: 10
+EOF
+       git commit --amend -F text &&
+       (
+               test_set_editor .git/FAKE_EDITOR &&
+               test_must_fail git -c core.commentChar=auto commit --amend
+       )
+'
+
 test_done