Sync with 1.5.6.5

diff --cc Documentation/git-diff-tree.txt
index 8c8f35b7a762d42d3c45ff9f4eee1cb32d3917b6,5d23985b570280baf30746f9749751aa079c7e76..1fdf20dcc9169be2c7a51b32f94893442e160436
--- 1/Documentation/git-diff-tree.txt
--- 2/Documentation/git-diff-tree.txt
+++ b/Documentation/git-diff-tree.txt
@@@ -54,11 -54,11 +54,11 @@@ include::diff-options.txt[
  +
  When a single commit is given on one line of such input, it compares
  the commit with its parents.  The following flags further affects its
- behavior.  This does not apply to the case where two <tree-ish>
- separated with a single space are given.
+ behavior.  The remaining commits, when given, are used as if they are
+ parents of the first commit.
  
  -m::
 -      By default, "git-diff-tree --stdin" does not show
 +      By default, 'git-diff-tree --stdin' does not show
        differences for merge commits.  With this flag, it shows
        differences to that commit from all of its parents. See
        also '-c'.

diff --cc Documentation/git.txt
Simple merge

diff --cc builtin-commit.c
Simple merge

diff --cc builtin-tag.c
Simple merge

diff --cc parse-options.c
Simple merge

diff --cc parse-options.h
Simple merge

diff --cc t/t7004-tag.sh
Simple merge

diff --cc t/t7500-commit.sh
Simple merge