apply: treat EOF as proper context.

Catalin noticed that we do not treat end-of-file condition shown
in the patch text as the patch context.  This causes a patch
that appends at the end of the file to cleanly apply even if
something else has been appended to the file.  If this happened
in the middle, we would refuse by saying that the file has
conflicting modifications.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

apply.c

@@ -1333,6 +1333,7 @@ static int apply_line(char *output, const char *patch, int plen)
 
 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
 {
+	int match_end;
 	char *buf = desc->buffer;
 	const char *patch = frag->patch;
 	int offset, size = frag->size;
@@ -1395,10 +1396,19 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
 	newlines = new;
 	leading = frag->leading;
 	trailing = frag->trailing;
+
+	/*
+	 * If we don't have any trailing data in the patch,
+	 * we want it to match at the end of the file.
+	 */
+	match_end = !trailing;
+
 	lines = 0;
 	pos = frag->newpos;
 	for (;;) {
 		offset = find_offset(buf, desc->size, oldlines, oldsize, pos, &lines);
+		if (match_end && offset + oldsize != desc->size)
+			offset = -1;
 		if (offset >= 0) {
 			int diff = newsize - oldsize;
 			unsigned long size = desc->size + diff;
@@ -1428,6 +1438,10 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
 		/* Am I at my context limits? */
 		if ((leading <= p_context) && (trailing <= p_context))
 			break;
+		if (match_end) {
+			match_end = 0;
+			continue;
+		}
 		/* Reduce the number of context lines
 		 * Reduce both leading and trailing if they are equal
 		 * otherwise just reduce the larger context.