Re: [PATCH] diffcore-rename: favour identical basenames

Hi,

On Fri, 22 Jun 2007, Jeff King wrote:

On Fri, Jun 22, 2007 at 02:14:43AM +0100, Johannes Schindelin wrote:

quoted

@@ -313,20 +297,24 @@ void diffcore_rename(struct diff_options *options)
 			if (rename_dst[i].pair)
 				continue; /* dealt with an earlier round */
 			for (j = 0; j < rename_src_nr; j++) {
-				int k;
+				int k, distance;
 				struct diff_filespec *one = rename_src[j].one;
 				if (!is_exact_match(one, two, contents_too))
 					continue;
 
+				distance = levenshtein(one->path, two->path);
 				/* see if there is a basename match, too */
 				for (k = j; k < rename_src_nr; k++) {

This loop can start at k = j+1, since otherwise we are just checking
rename_src[j] against itself.

Right.

quoted

+int levenshtein(const char *string1, const char *string2)
+{
+	int len1 = strlen(string1), len2 = strlen(string2);
+	int *row1 = xmalloc(sizeof(int) * (len2 + 1));
+	int *row2 = xmalloc(sizeof(int) * (len2 + 1));
+	int i, j;
+
+	for (j = 1; j <= len2; j++)
+		row1[j] = j;

This loop must start at j=0, not j=1; otherwise you have an undefined
value in row1[0], which gets read when setting row2[1], and you get
a totally meaningless distance (I got -1209667248 on my test case!).

Sorry for that. I originally had an xcalloc in there, and did not look at 
that loop afterwards.

And I completely forgot that on my laptop (on which I did this patch), I 
had forgotten to add

	ALL_CFLAGS += -DXMALLOC_POISON=1

to config.mak.

Ciao,
Dscho