[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>
This commit is contained in:
Junio C Hamano
2005-05-30 00:08:37 -07:00
committed by Linus Torvalds
parent 2cd68882ee
commit f345b0a066
13 changed files with 433 additions and 29 deletions

21
diff.c
View File

@ -603,6 +603,7 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
dp->two = two;
dp->score = 0;
dp->source_stays = 0;
dp->broken_pair = 0;
diff_q(queue, dp);
return dp;
}
@ -637,6 +638,16 @@ static void diff_flush_raw(struct diff_filepair *p,
sprintf(status, "%c%03d", p->status,
(int)(0.5 + p->score * 100.0/MAX_SCORE));
break;
case 'N': case 'D':
two_paths = 0;
if (p->score)
sprintf(status, "%c%03d", p->status,
(int)(0.5 + p->score * 100.0/MAX_SCORE));
else {
status[0] = p->status;
status[1] = 0;
}
break;
default:
two_paths = 0;
status[0] = p->status;
@ -760,8 +771,9 @@ void diff_debug_filepair(const struct diff_filepair *p, int i)
{
diff_debug_filespec(p->one, i, "one");
diff_debug_filespec(p->two, i, "two");
fprintf(stderr, "score %d, status %c source_stays %d\n",
p->score, p->status ? : '?', p->source_stays);
fprintf(stderr, "score %d, status %c stays %d broken %d\n",
p->score, p->status ? : '?',
p->source_stays, p->broken_pair);
}
void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
@ -875,10 +887,13 @@ void diff_flush(int diff_output_style, int resolve_rename_copy)
void diffcore_std(const char **paths,
int detect_rename, int rename_score,
const char *pickaxe, int pickaxe_opts)
const char *pickaxe, int pickaxe_opts,
int break_opt)
{
if (paths && paths[0])
diffcore_pathspec(paths);
if (0 <= break_opt)
diffcore_break(break_opt);
if (detect_rename)
diffcore_rename(detect_rename, rename_score);
if (pickaxe)