combine-diff: move the code to parse hunk-header into common library.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 46 insertions, 0 deletions

diff --git a/xdiff-interface.c b/xdiff-interface.c
index 0a66ded..f7d6f98 100644
--- a/xdiff-interface.c
+++ b/xdiff-interface.c
@@ -1,6 +1,52 @@
 #include "cache.h"
 #include "xdiff-interface.h"
 
+static int parse_num(char **cp_p, unsigned int *num_p)
+{
+	char *cp = *cp_p;
+	unsigned int num = 0;
+	int read_some;
+
+	while ('0' <= *cp && *cp <= '9')
+		num = num * 10 + *cp++ - '0';
+	if (!(read_some = cp - *cp_p))
+		return -1;
+	*cp_p = cp;
+	*num_p = num;
+	return 0;
+}
+
+int parse_hunk_header(char *line, int len,
+		      unsigned int *ob, unsigned int *on,
+		      unsigned int *nb, unsigned int *nn)
+{
+	char *cp;
+	cp = line + 4;
+	if (parse_num(&cp, ob)) {
+	bad_line:
+		return error("malformed diff output: %s", line);
+	}
+	if (*cp == ',') {
+		cp++;
+		if (parse_num(&cp, on))
+			goto bad_line;
+	}
+	else
+		*on = 1;
+	if (*cp++ != ' ' || *cp++ != '+')
+		goto bad_line;
+	if (parse_num(&cp, nb))
+		goto bad_line;
+	if (*cp == ',') {
+		cp++;
+		if (parse_num(&cp, nn))
+			goto bad_line;
+	}
+	else
+		*nn = 1;
+	return -!!memcmp(cp, " @@", 3);
+}
+
 static void consume_one(void *priv_, char *s, unsigned long size)
 {
 	struct xdiff_emit_state *priv = priv_;