@matheusbsbs / matheus-bagliano / commits / 12426e114b

diff: do not short-cut CHECK_SIZE_ONLY check in diff_populate_filespec()

Callers of diff_populate_filespec() can choose to ask only for the size of the blob without grabbing the blob data, and the function, after running lstat() when the filespec points at a working tree file, returns by copying the value in size field of the stat structure into the size field of the filespec when this is the case. However, this short-cut cannot be taken if the contents from the path needs to go through convert_to_git(), whose resulting real blob data may be different from what is in the working tree file. As "git diff --quiet" compares the .size fields of filespec structures to skip content comparison, this bug manifests as a false "there are differences" for a file that needs eol conversion, for example. Reported-by: Mike Crowe <mac@mcrowe.com> Helped-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Junio C Hamano committed Mar 1, 2017 at 18:04 UTC 12426e114b252d130d83c3f098c4ceae3cf217e3

2 files changed +27 -1

diff.c

+18 -1

@@ -2783,8 +2783,25 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)

2783 s->should_free = 1;

2784 return 0;

2785 }

2786 - if (size_only)

2786 +

2787 + /*

2788 + * Even if the caller would be happy with getting

2789 + * only the size, we cannot return early at this

2790 + * point if the path requires us to run the content

2791 + * conversion.

2792 + */

2793 + if (size_only && !would_convert_to_git(s->path))

2794 return 0;

2795 +

2796 + /*

2797 + * Note: this check uses xsize_t(st.st_size) that may

2798 + * not be the true size of the blob after it goes

2799 + * through convert_to_git(). This may not strictly be

2800 + * correct, but the whole point of big_file_threshold

2801 + * and is_binary check being that we want to avoid

2802 + * opening the file and inspecting the contents, this

2803 + * is probably fine.

2804 + */

2805 if ((flags & CHECK_BINARY) &&

2806 s->size > big_file_threshold && s->is_binary == -1) {

2807 s->is_binary = 1;

t/t4035-diff-quiet.sh

@@ -152,4 +152,13 @@ test_expect_success 'git diff --quiet ignores stat-change only entries' '

152 test_expect_code 1 git diff --quiet

153 '

154

155 +test_expect_success 'git diff --quiet on a path that need conversion' '

156 + echo "crlf.txt text=auto" >.gitattributes &&

157 + printf "Hello\r\nWorld\r\n" >crlf.txt &&

158 + git add .gitattributes crlf.txt &&

159 +

160 + printf "Hello\r\nWorld\n" >crlf.txt &&

161 + git diff --quiet crlf.txt

162 +'

163 +

164 test_done