[PATCH] diff: Fix rename pretty-print when suffix and prefix overlap
From: Antoine Pelisse <hidden>
Date: 2016-06-15 22:56:17
Subsystem:
the rest · Maintainer:
Linus Torvalds
When considering a rename for two files that have a suffix and a prefix
that can overlap, a confusing line is shown. As an example, renaming
"a/b/b/c" to "a/b/c" shows "a/b/{ => }/b/c", instead of "a/b/{b => }/c"
Currently, what we do is calculate the common prefix ("a/b/"), and the
common suffix ("/b/c"), but the same "/b/" is actually counted both in
prefix and suffix. Then when calculating the size of the non-common part,
we end-up with a negative value which is reset to 0, thus the "{ => }".
Do not allow the common suffix to overlap the common prefix and stop
when reaching a "/" that would be in both.
Also add some test file to place corner-cases we could met (and this one)
with rename pretty print.
Signed-off-by: Antoine Pelisse <redacted>
---
diff.c | 11 +++++++++-
t/t4056-rename-pretty.sh | 54 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 64 insertions(+), 1 deletion(-)
create mode 100755 t/t4056-rename-pretty.sh
diff --git a/diff.c b/diff.c
index 9038f19..e1d82c9 100644
--- a/diff.c
+++ b/diff.c@@ -1177,7 +1177,16 @@ static char *pprint_rename(const char *a, const char *b) old = a + len_a; new = b + len_b; sfx_length = 0; - while (a <= old && b <= new && *old == *new) { + /* + * Note: + * if pfx_length is 0, old/new will never reach a - 1 because it + * would mean the whole string is common suffix. But then, the + * whole string would also be a common prefix, and we would not + * have pfx_length equals 0. + */ + while (a + pfx_length - 1 <= old && + b + pfx_length - 1 <= new && + *old == *new) { if (*old == '/') sfx_length = len_a - (old - a); old--;
diff --git a/t/t4056-rename-pretty.sh b/t/t4056-rename-pretty.sh
new file mode 100755
index 0000000..806046f
--- /dev/null
+++ b/t/t4056-rename-pretty.sh@@ -0,0 +1,54 @@ +#!/bin/sh + +test_description='Rename pretty print + +' + +. ./test-lib.sh + +test_expect_success nothing_common ' + mkdir -p a/b/ && + : >a/b/c && + git add a/b/c && + git commit -m. && + mkdir -p c/b/ && + git mv a/b/c c/b/a && + git commit -m. && + git show -M --summary >output && + test_i18ngrep "a/b/c => c/b/a" output +' + +test_expect_success common_prefix ' + mkdir -p c/d && + git mv c/b/a c/d/e && + git commit -m. && + git show -M --summary >output && + test_i18ngrep "c/{b/a => d/e}" output +' + +test_expect_success common_suffix ' + mkdir d && + git mv c/d/e d/e && + git commit -m. && + git show -M --summary >output && + test_i18ngrep "{c/d => d}/e" output +' + +test_expect_success common_suffix_prefix ' + mkdir d/f && + git mv d/e d/f/e && + git commit -m. && + git show -M --summary >output && + test_i18ngrep "d/{ => f}/e" output +' + +test_expect_success common_overlap ' + mkdir d/f/f && + git mv d/f/e d/f/f/e && + git commit -m. && + git show -M --summary >output && + test_i18ngrep "d/f/{ => f}/e" output +' + + +test_done --
1.7.9.5