pathspec: create parse_short_magic function

Factor out the logic responsible for parsing short magic into its own
function.

Signed-off-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

pathspec.c

@@ -156,6 +156,41 @@ static int get_global_magic(int element_magic)
 	return global_magic;
 }
 
+/*
+ * Parse the pathspec element looking for short magic
+ *
+ * saves all magic in 'magic'
+ * returns the position in 'elem' after all magic has been parsed
+ */
+static const char *parse_short_magic(unsigned *magic, const char *elem)
+{
+	const char *pos;
+
+	for (pos = elem + 1; *pos && *pos != ':'; pos++) {
+		char ch = *pos;
+		int i;
+
+		if (!is_pathspec_magic(ch))
+			break;
+
+		for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
+			if (pathspec_magic[i].mnemonic == ch) {
+				*magic |= pathspec_magic[i].bit;
+				break;
+			}
+		}
+
+		if (ARRAY_SIZE(pathspec_magic) <= i)
+			die(_("Unimplemented pathspec magic '%c' in '%s'"),
+			    ch, elem);
+	}
+
+	if (*pos == ':')
+		pos++;
+
+	return pos;
+}
+
 /*
  * Take an element of a pathspec and check for magic signatures.
  * Append the result to the prefix. Return the magic bitmap.
@@ -220,24 +255,7 @@ static unsigned prefix_pathspec(struct pathspec_item *item, unsigned flags,
 		copyfrom++;
 	} else {
 		/* shorthand */
-		for (copyfrom = elt + 1;
+		copyfrom = parse_short_magic(&element_magic, elt);
-		     *copyfrom && *copyfrom != ':';
-		     copyfrom++) {
-			char ch = *copyfrom;
-
-			if (!is_pathspec_magic(ch))
-				break;
-			for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
-				if (pathspec_magic[i].mnemonic == ch) {
-					element_magic |= pathspec_magic[i].bit;
-					break;
-				}
-			if (ARRAY_SIZE(pathspec_magic) <= i)
-				die(_("Unimplemented pathspec magic '%c' in '%s'"),
-				    ch, elt);
-		}
-		if (*copyfrom == ':')
-			copyfrom++;
 	}
 
 	magic |= element_magic;