X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=Documentation%2Fdiff-format.txt;h=001503205b24d5c20ec10792c4ab6c4c7221bcb7;hb=84d176cef65ad23e11643d463c69ad313b728eda;hp=378e72f38f37eef50135c3907ccd605652f4fd96;hpb=5bac4a671907604b5fb4e24ff682d5b0e8431931;p=git.git

diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt
index 378e72f38..001503205 100644
--- a/Documentation/diff-format.txt
+++ b/Documentation/diff-format.txt
@@ -1,7 +1,7 @@
 The output format from "git-diff-index", "git-diff-tree" and
 "git-diff-files" are very similar.
 
-These commands all compare two sets of things; what is 
+These commands all compare two sets of things; what is
 compared differs:
 
 git-diff-index <tree-ish>::
@@ -59,6 +59,28 @@ When `-z` option is not used, TAB, LF, and backslash characters
 in pathnames are represented as `\t`, `\n`, and `\\`,
 respectively.
 
+diff format for merges
+----------------------
+
+"git-diff-tree" and "git-diff-files" can take '-c' or '--cc' option
+to generate diff output also for merge commits.  The output differs
+from the format described above in the following way:
+
+. there is a colon for each parent
+. there are more "src" modes and "src" sha1
+. status is concatenated status characters for each parent
+. no optional "score" number
+. single path, only for "dst"
+
+Example:
+
+------------------------------------------------
+::100644 100644 100644 fabadb8... cc95eb0... 4866510... MM	describe.c
+------------------------------------------------
+
+Note that 'combined diff' lists only files which were modified from
+all parents.
+
 
 Generating patches with -p
 --------------------------
@@ -104,6 +126,13 @@ the file that rename/copy produces, respectively.
     If there is need for such substitution then the whole
     pathname is put in double quotes.
 
+The similarity index is the percentage of unchanged lines, and
+the dissimilarity index is the percentage of changed lines.  It
+is a rounded down integer, followed by a percent sign.  The
+similarity index value of 100% is thus reserved for two equal
+files, while 100% dissimilarity means that no line from the old
+file made it into the new one.
+
 
 combined diff format
 --------------------
@@ -117,28 +146,28 @@ index fabadb8,cc95eb0..4866510
 --- a/describe.c
 +++ b/describe.c
 @@@ -98,20 -98,12 +98,20 @@@
-  	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
+	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
   }
-  
+
 - static void describe(char *arg)
  -static void describe(struct commit *cmit, int last_one)
 ++static void describe(char *arg, int last_one)
   {
  +	unsigned char sha1[20];
  +	struct commit *cmit;
-  	struct commit_list *list;
-  	static int initialized = 0;
-  	struct commit_name *n;
-  
+	struct commit_list *list;
+	static int initialized = 0;
+	struct commit_name *n;
+
  +	if (get_sha1(arg, sha1) < 0)
  +		usage(describe_usage);
  +	cmit = lookup_commit_reference(sha1);
  +	if (!cmit)
  +		usage(describe_usage);
  +
-  	if (!initialized) {
-  		initialized = 1;
-  		for_each_ref(get_name);
+	if (!initialized) {
+		initialized = 1;
+		for_each_ref(get_name);
 ------------
 
 1.   It is preceded with a "git diff" header, that looks like
@@ -211,4 +240,3 @@ parents).  When shown by `git diff-files -c`, it compares the
 two unresolved merge parents with the working tree file
 (i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka
 "their version").
-