[PATCH] Add -B flag to diff-* brothers.
A new diffcore transformation, diffcore-break.c, is introduced.
When the -B flag is given, a patch that represents a complete
rewrite is broken into a deletion followed by a creation. This
makes it easier to review such a complete rewrite patch.
The -B flag takes the same syntax as the -M and -C flags to
specify the minimum amount of non-source material the resulting
file needs to have to be considered a complete rewrite, and
defaults to 99% if not specified.
As the new test t4008-diff-break-rewrite.sh demonstrates, if a
file is a complete rewrite, it is broken into a delete/create
pair, which can further be subjected to the usual rename
detection if -M or -C is used. For example, if file0 gets
completely rewritten to make it as if it were rather based on
file1 which itself disappeared, the following happens:
The original change looks like this:
file0 --> file0' (quite different from file0)
file1 --> /dev/null
After diffcore-break runs, it would become this:
file0 --> /dev/null
/dev/null --> file0'
file1 --> /dev/null
Then diffcore-rename matches them up:
file1 --> file0'
The internal score values are finer grained now. Earlier
maximum of 10000 has been raised to 60000; there is no user
visible changes but there is no reason to waste available bits.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/diff-files.c b/diff-files.c
index 3f20e7e..b840b35 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -15,6 +15,7 @@
static int diff_score_opt = 0;
static const char *pickaxe = NULL;
static int pickaxe_opts = 0;
+static int diff_break_opt = -1;
static int silent = 0;
static void show_unmerge(const char *path)
@@ -57,6 +58,8 @@
pickaxe = argv[1] + 2;
else if (!strcmp(argv[1], "--pickaxe-all"))
pickaxe_opts = DIFF_PICKAXE_ALL;
+ else if (!strncmp(argv[1], "-B", 2))
+ diff_break_opt = diff_scoreopt_parse(argv[1]);
else if (!strncmp(argv[1], "-M", 2)) {
diff_score_opt = diff_scoreopt_parse(argv[1]);
detect_rename = DIFF_DETECT_RENAME;
@@ -116,9 +119,10 @@
show_modified(oldmode, mode, ce->sha1, null_sha1,
ce->name);
}
- diffcore_std(argv + 1,
+ diffcore_std((1 < argc) ? argv + 1 : NULL,
detect_rename, diff_score_opt,
- pickaxe, pickaxe_opts);
+ pickaxe, pickaxe_opts,
+ diff_break_opt);
diff_flush(diff_output_format, 1);
return 0;
}
