kernel
/
git
mirror of https://git.kernel.org/pub/scm/git/git.git
1
0
Fork 0
Code Releases Activity

history: streamline message preparation and plug file stream leak 

An early part of fill_commit_message() function uses write_file_buf()
to write out what was prepared in a strbuf, which is primarily meant
for use by callers that have their own message prepared fully and
called as the last thing to flush it to the destination file.

However, the function then opens a file stream in append mode to
further write into it.  It may have been understandable if this was
a later addition, but it seems it came from a single commit,
d205234c (builtin/history: implement "reword" subcommand,
2026-01-13), which is somewhat puzzling, but anyway...

Just open the file stream upfront for writing, write the message
the function has in the strbuf, and then keep writing whatever it
wants to write to the same open file stream.

And do not forget to close the stream.  We are about to pass the
resulting file to an external editor, and on some systems, notably
Windows, you are not supposed to keep a file open while expecting
another program to access it.

Diagnosed-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
next
Junio C Hamano 2026-06-29 09:08:42 -07:00
parent d205234cb0
commit ebb4d2ffa3
1 changed files with 10 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
builtin/history.c
View File

@ -41,11 +41,6 @@ static int fill_commit_message(struct repository *repo,
" empty message aborts the commit.\n");
struct wt_status s;

strbuf_addstr(out, default_message);
strbuf_addch(out, '\n');
strbuf_commented_addf(out, comment_line_str, hint, action, comment_line_str);
write_file_buf(path, out->buf, out->len);

wt_status_prepare(repo, &s);
FREE_AND_NULL(s.branch);
s.ahead_behind_flags = AHEAD_BEHIND_QUICK;
@ -57,14 +52,22 @@ static int fill_commit_message(struct repository *repo,
s.whence = FROM_COMMIT;
s.committable = 1;

s.fp = fopen(git_path_commit_editmsg(), "a");
s.fp = fopen(path, "w");
if (!s.fp)
return error_errno(_("could not open '%s'"), git_path_commit_editmsg());
return error_errno(_("could not open '%s'"), path);

strbuf_addstr(out, default_message);
strbuf_addch(out, '\n');
strbuf_commented_addf(out, comment_line_str, hint, action, comment_line_str);
if (fwrite(out->buf, 1, out->len, s.fp) != out->len)
die_errno(_("could not write to '%s'"), path);

wt_status_collect_changes_trees(&s, old_tree, new_tree);
wt_status_print(&s);
wt_status_collect_free_buffers(&s);
string_list_clear_func(&s.change, change_data_free);
if (fclose(s.fp))
die_errno(_("could not write to '%s'"), path);

strbuf_reset(out);
if (launch_editor(path, out, NULL)) {