From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 14 Feb 2013 18:28:48 +0000 (-0800)
Subject: Merge branch 'jc/extended-fake-ancestor-for-gitlink'
X-Git-Tag: v1.8.2-rc0~24
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/d3354cde33e2674493969a1870c9771ea0921084?hp=-c

Merge branch 'jc/extended-fake-ancestor-for-gitlink'

Instead of requiring the full 40-hex object names on the index
line, we can read submodule commit object names from the textual
diff when synthesizing a fake ancestore tree for "git am -3".

* jc/extended-fake-ancestor-for-gitlink:
apply: verify submodule commit object name better
---

d3354cde33e2674493969a1870c9771ea0921084
diff --combined builtin/apply.c
index 080ce2ea3e,445fea7af6..06f5320b18
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@@ -1041,17 -1041,15 +1041,17 @@@ static int gitdiff_renamedst(const cha
  
  static int gitdiff_similarity(const char *line, struct patch *patch)
  {
 -	if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 -		patch->score = 0;
 +	unsigned long val = strtoul(line, NULL, 10);
 +	if (val <= 100)
 +		patch->score = val;
  	return 0;
  }
  
  static int gitdiff_dissimilarity(const char *line, struct patch *patch)
  {
 -	if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
 -		patch->score = 0;
 +	unsigned long val = strtoul(line, NULL, 10);
 +	if (val <= 100)
 +		patch->score = val;
  	return 0;
  }
  
@@@ -2097,7 -2095,7 +2097,7 @@@ static void update_pre_post_images(stru
  				   char *buf,
  				   size_t len, size_t postlen)
  {
 -	int i, ctx;
 +	int i, ctx, reduced;
  	char *new, *old, *fixed;
  	struct image fixed_preimage;
  
@@@ -2107,10 -2105,8 +2107,10 @@@
  	 * free "oldlines".
  	 */
  	prepare_image(&fixed_preimage, buf, len, 1);
 -	assert(fixed_preimage.nr == preimage->nr);
 -	for (i = 0; i < preimage->nr; i++)
 +	assert(postlen
 +	       ? fixed_preimage.nr == preimage->nr
 +	       : fixed_preimage.nr <= preimage->nr);
 +	for (i = 0; i < fixed_preimage.nr; i++)
  		fixed_preimage.line[i].flag = preimage->line[i].flag;
  	free(preimage->line_allocated);
  	*preimage = fixed_preimage;
@@@ -2130,8 -2126,7 +2130,8 @@@
  	else
  		new = old;
  	fixed = preimage->buf;
 -	for (i = ctx = 0; i < postimage->nr; i++) {
 +
 +	for (i = reduced = ctx = 0; i < postimage->nr; i++) {
  		size_t len = postimage->line[i].len;
  		if (!(postimage->line[i].flag & LINE_COMMON)) {
  			/* an added line -- no counterparts in preimage */
@@@ -2150,15 -2145,8 +2150,15 @@@
  			fixed += preimage->line[ctx].len;
  			ctx++;
  		}
 -		if (preimage->nr <= ctx)
 -			die(_("oops"));
 +
 +		/*
 +		 * preimage is expected to run out, if the caller
 +		 * fixed addition of trailing blank lines.
 +		 */
 +		if (preimage->nr <= ctx) {
 +			reduced++;
 +			continue;
 +		}
  
  		/* and copy it in, while fixing the line length */
  		len = preimage->line[ctx].len;
@@@ -2171,7 -2159,6 +2171,7 @@@
  
  	/* Fix the length of the whole thing */
  	postimage->len = new - postimage->buf;
 +	postimage->nr -= reduced;
  }
  
  static int match_fragment(struct image *img,
@@@ -3600,6 -3587,40 +3600,40 @@@ static int get_current_sha1(const char 
  	return 0;
  }
  
+ static int preimage_sha1_in_gitlink_patch(struct patch *p, unsigned char sha1[20])
+ {
+ 	/*
+ 	 * A usable gitlink patch has only one fragment (hunk) that looks like:
+ 	 * @@ -1 +1 @@
+ 	 * -Subproject commit <old sha1>
+ 	 * +Subproject commit <new sha1>
+ 	 * or
+ 	 * @@ -1 +0,0 @@
+ 	 * -Subproject commit <old sha1>
+ 	 * for a removal patch.
+ 	 */
+ 	struct fragment *hunk = p->fragments;
+ 	static const char heading[] = "-Subproject commit ";
+ 	char *preimage;
+ 
+ 	if (/* does the patch have only one hunk? */
+ 	    hunk && !hunk->next &&
+ 	    /* is its preimage one line? */
+ 	    hunk->oldpos == 1 && hunk->oldlines == 1 &&
+ 	    /* does preimage begin with the heading? */
+ 	    (preimage = memchr(hunk->patch, '\n', hunk->size)) != NULL &&
+ 	    !prefixcmp(++preimage, heading) &&
+ 	    /* does it record full SHA-1? */
+ 	    !get_sha1_hex(preimage + sizeof(heading) - 1, sha1) &&
+ 	    preimage[sizeof(heading) + 40 - 1] == '\n' &&
+ 	    /* does the abbreviated name on the index line agree with it? */
+ 	    !prefixcmp(preimage + sizeof(heading) - 1, p->old_sha1_prefix))
+ 		return 0; /* it all looks fine */
+ 
+ 	/* we may have full object name on the index line */
+ 	return get_sha1_hex(p->old_sha1_prefix, sha1);
+ }
+ 
  /* Build an index that contains the just the files needed for a 3way merge */
  static void build_fake_ancestor(struct patch *list, const char *filename)
  {
@@@ -3620,8 -3641,10 +3654,10 @@@
  			continue;
  
  		if (S_ISGITLINK(patch->old_mode)) {
- 			if (get_sha1_hex(patch->old_sha1_prefix, sha1))
- 				die("submoule change for %s without full index name",
+ 			if (!preimage_sha1_in_gitlink_patch(patch, sha1))
+ 				; /* ok, the textual part looks sane */
+ 			else
+ 				die("sha1 information is lacking or useless for submoule %s",
  				    name);
  		} else if (!get_sha1_blob(patch->old_sha1_prefix, sha1)) {
  			; /* ok */