[PATCH] Fix the way diffcore-rename records unremoved source.

Earier version of diffcore-rename used to keep unmodified
filepair in its output so that the last stage of the processing
that tells renames from copies can make all of rename/copy to
copies.  However this had a bad interaction with other diffcore
filters that wanted to run after diffcore-rename, in that such
unmodified filepair must be retained for proper distinction
between renames and copies to happen.

This patch fixes the problem by changing the way diffcore-rename
records the information needed to distinguish "all are copies"
case and "the last one is a rename" case.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 103 insertions, 0 deletions

diff --git a/t/t4007-rename-3.sh b/t/t4007-rename-3.sh
new file mode 100644
index 0000000000..cf18440977
--- /dev/null
+++ b/t/t4007-rename-3.sh
@@ -0,0 +1,103 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+#
+
+test_description='Rename interaction with pathspec.
+
+'
+. ./test-lib.sh
+
+_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
+_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
+sanitize_diff_raw='s/ \('"$_x40"'\) \1 \([CR]\)[0-9]*	/ \1 \1 \2#	/'
+compare_diff_raw () {
+    # When heuristics are improved, the score numbers would change.
+    # Ignore them while comparing.
+    # Also we do not check SHA1 hash generation in this test, which
+    # is a job for t0000-basic.sh
+
+    sed -e "$sanitize_diff_raw" <"$1" >.tmp-1
+    sed -e "$sanitize_diff_raw" <"$2" >.tmp-2
+    diff -u .tmp-1 .tmp-2 && rm -f .tmp-1 .tmp-2
+}
+
+test_expect_success \
+    'prepare reference tree' \
+    'mkdir path0 path1 &&
+     cp ../../COPYING path0/COPYING &&
+     git-update-cache --add path0/COPYING &&
+    tree=$(git-write-tree) &&
+    echo $tree'
+
+test_expect_success \
+    'prepare work tree' \
+    'cp path0/COPYING path1/COPYING &&
+     git-update-cache --add --remove path0/COPYING path1/COPYING'
+
+# In the tree, there is only path0/COPYING.  In the cache, path0 and
+# path1 both have COPYING and the latter is a copy of path0/COPYING.
+# Comparing the full tree with cache should tell us so.
+
+git-diff-cache -C $tree >current
+
+cat >expected <<\EOF
+:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 6ff87c4664981e4397625791c8ea3bbb5f2279a3 C100	path0/COPYING	path1/COPYING
+EOF
+
+test_expect_success \
+    'validate the result' \
+    'compare_diff_raw current expected'
+
+# In the tree, there is only path0/COPYING.  In the cache, path0 and
+# path1 both have COPYING and the latter is a copy of path0/COPYING.
+# When we omit output from path0 it should still be able to tell us
+# that path1/COPYING is result from a copy from path0/COPYING, not
+# rename, which would imply path0/COPYING is now gone.
+
+git-diff-cache -C $tree path1 >current
+
+cat >expected <<\EOF
+:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 6ff87c4664981e4397625791c8ea3bbb5f2279a3 C100	path0/COPYING	path1/COPYING
+EOF
+
+test_expect_success \
+    'validate the result' \
+    'compare_diff_raw current expected'
+
+test_expect_success \
+    'tweak work tree' \
+    'rm -f path0/COPYING &&
+     git-update-cache --remove path0/COPYING'
+
+# In the tree, there is only path0/COPYING.  In the cache, path0 does
+# not have COPYING anymore and path1 has COPYING which is a copy of
+# path0/COPYING.  Showing the full tree with cache should tell us about
+# the rename.
+
+git-diff-cache -C $tree >current
+
+cat >expected <<\EOF
+:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 6ff87c4664981e4397625791c8ea3bbb5f2279a3 R100	path0/COPYING	path1/COPYING
+EOF
+
+test_expect_success \
+    'validate the result' \
+    'compare_diff_raw current expected'
+
+# In the tree, there is only path0/COPYING.  In the cache, path0 does
+# not have COPYING anymore and path1 has COPYING which is a copy of
+# path0/COPYING.  Even if we restrict the output to path1, it still
+# should show us the rename.
+
+git-diff-cache -C $tree path1 >current
+
+cat >expected <<\EOF
+:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 6ff87c4664981e4397625791c8ea3bbb5f2279a3 R100	path0/COPYING	path1/COPYING
+EOF
+
+test_expect_success \
+    'validate the result' \
+    'compare_diff_raw current expected'
+
+test_done