From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 7 Apr 2008 03:04:29 +0000 (-0700)
Subject: Merge branch 'jc/maint-apply-match-beginning'
X-Git-Tag: v1.5.5~3
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=a1c0dca43a3513574e5bebb38989671960cdaf35;p=git.git

Merge branch 'jc/maint-apply-match-beginning'

* jc/maint-apply-match-beginning:
  Fix "git apply" to correctly enforce "match at the beginning"
---

a1c0dca43a3513574e5bebb38989671960cdaf35
diff --cc builtin-apply.c
index b5f78ac3a,03f2e950b..abe73a0f8
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@@ -1937,37 -1736,52 +1937,40 @@@ static int apply_one_fragment(struct im
  	trailing = frag->trailing;
  
  	/*
- 	 * If we don't have any leading/trailing data in the patch,
- 	 * we want it to match at the beginning/end of the file.
+ 	 * A hunk to change lines at the beginning would begin with
+ 	 * @@ -1,L +N,M @@
  	 *
- 	 * But that would break if the patch is generated with
- 	 * --unified=0; sane people wouldn't do that to cause us
- 	 * trouble, but we try to please not so sane ones as well.
+ 	 * And a hunk to add to an empty file would begin with
+ 	 * @@ -0,0 +N,M @@
+ 	 *
+ 	 * In other words, a hunk that is (frag->oldpos <= 1) with or
+ 	 * without leading context must match at the beginning.
  	 */
- 	if (unidiff_zero) {
- 		match_beginning = (!leading && !frag->oldpos);
- 		match_end = 0;
- 	}
- 	else {
- 		match_beginning = !leading && (frag->oldpos == 1);
- 		match_end = !trailing;
- 	}
+ 	match_beginning = frag->oldpos <= 1;
+ 
+ 	/*
+ 	 * A hunk without trailing lines must match at the end.
+ 	 * However, we simply cannot tell if a hunk must match end
+ 	 * from the lack of trailing lines if the patch was generated
+ 	 * with unidiff without any context.
+ 	 */
+ 	match_end = !unidiff_zero && !trailing;
  
 -	lines = 0;
 -	pos = frag->newpos;
 +	pos = frag->newpos ? (frag->newpos - 1) : 0;
 +	preimage.buf = oldlines;
 +	preimage.len = old - oldlines;
 +	postimage.buf = newlines;
 +	postimage.len = new - newlines;
 +	preimage.line = preimage.line_allocated;
 +	postimage.line = postimage.line_allocated;
 +
  	for (;;) {
 -		offset = find_offset(buf->buf, buf->len,
 -				     oldlines, oldsize, pos, &lines);
 -		if (match_end && offset + oldsize != buf->len)
 -			offset = -1;
 -		if (match_beginning && offset)
 -			offset = -1;
 -		if (offset >= 0) {
 -			if (ws_error_action == correct_ws_error &&
 -			    (buf->len - oldsize - offset == 0)) /* end of file? */
 -				newsize -= new_blank_lines_at_end;
 -
 -			/* Warn if it was necessary to reduce the number
 -			 * of context lines.
 -			 */
 -			if ((leading != frag->leading) ||
 -			    (trailing != frag->trailing))
 -				fprintf(stderr, "Context reduced to (%ld/%ld)"
 -					" to apply fragment at %d\n",
 -					leading, trailing, pos + lines);
 -
 -			strbuf_splice(buf, offset, oldsize, newlines, newsize);
 -			offset = 0;
 +
 +		applied_pos = find_pos(img, &preimage, &postimage, pos,
 +				       ws_rule, match_beginning, match_end);
 +
 +		if (applied_pos >= 0)
  			break;
 -		}
  
  		/* Am I at my context limits? */
  		if ((leading <= p_context) && (trailing <= p_context))