"git diff <tree>{3,}": do not reverse order of arguments

According to the message of commit 0fe7c1de16f71312e6adac4b85bddf0d62a47168,
"git diff" with three or more trees expects the merged tree first followed by
the parents, in order.  However, this command reversed the order of its
arguments, resulting in confusing diffs.  A comment /* Again, the revs are all
reverse */ suggested there was a reason for this, but I can't figure out the
reason, so I removed the reversal of the arguments.  Test case included.

Signed-off-by: Matt McCutchen <matt@mattmccutchen.net>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/builtin-diff.c b/builtin-diff.c
index 35da366..9c8c295 100644 (file)
--- a/builtin-diff.c
+++ b/builtin-diff.c
@@ -177,10 +177,8 @@ static int builtin_diff_combined(struct rev_info *revs,
        if (!revs->dense_combined_merges && !revs->combine_merges)
                revs->dense_combined_merges = revs->combine_merges = 1;
        parent = xmalloc(ents * sizeof(*parent));
-       /* Again, the revs are all reverse */
        for (i = 0; i < ents; i++)
-               hashcpy((unsigned char *)(parent + i),
-                       ent[ents - 1 - i].item->sha1);
+               hashcpy((unsigned char *)(parent + i), ent[i].item->sha1);
        diff_tree_combined(parent[0], parent + 1, ents - 1,
                           revs->dense_combined_merges, revs);
        return 0;

diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 1a6b522..fe6080d 100755 (executable)
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -258,6 +258,7 @@ diff --patch-with-stat -r initial..side
 diff --patch-with-raw -r initial..side
 diff --name-status dir2 dir
 diff --no-index --name-status dir2 dir
+diff master master^ side
 EOF
 
 test_done

diff --git a/t/t4013/diff.diff_master_master^_side b/t/t4013/diff.diff_master_master^_side
new file mode 100644 (file)
index 0000000..50ec9ca
--- /dev/null
+++ b/t/t4013/diff.diff_master_master^_side
@@ -0,0 +1,29 @@
+$ git diff master master^ side
+diff --cc dir/sub
+index cead32e,7289e35..992913c
+--- a/dir/sub
++++ b/dir/sub
+@@@ -1,6 -1,4 +1,8 @@@
+  A
+  B
+ +C
+ +D
+ +E
+ +F
++ 1
++ 2
+diff --cc file0
+index b414108,f4615da..10a8a9f
+--- a/file0
++++ b/file0
+@@@ -1,6 -1,6 +1,9 @@@
+  1
+  2
+  3
+ +4
+ +5
+ +6
++ A
++ B
++ C
+$