commit: don't check for space twice when looking for header

Both standard_header_field() and excluded_header_field() check if
there's a space after the buffer that's handed to them.  We already
check in the caller if that space is present.  Don't bother calling
the functions if it's missing, as they are guaranteed to return 0 in
that case, and remove the now redundant checks from them.

Signed-off-by: Rene Scharfe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

commit.c

@@ -1308,11 +1308,11 @@ void for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
 
 static inline int standard_header_field(const char *field, size_t len)
 {
-	return ((len == 4 && !memcmp(field, "tree ", 5)) ||
-		(len == 6 && !memcmp(field, "parent ", 7)) ||
-		(len == 6 && !memcmp(field, "author ", 7)) ||
-		(len == 9 && !memcmp(field, "committer ", 10)) ||
-		(len == 8 && !memcmp(field, "encoding ", 9)));
+	return ((len == 4 && !memcmp(field, "tree", 4)) ||
+		(len == 6 && !memcmp(field, "parent", 6)) ||
+		(len == 6 && !memcmp(field, "author", 6)) ||
+		(len == 9 && !memcmp(field, "committer", 9)) ||
+		(len == 8 && !memcmp(field, "encoding", 8)));
 }
 
 static int excluded_header_field(const char *field, size_t len, const char **exclude)
@@ -1322,8 +1322,7 @@ static int excluded_header_field(const char *field, size_t len, const char **exc
 
 	while (*exclude) {
 		size_t xlen = strlen(*exclude);
-		if (len == xlen &&
-		    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
+		if (len == xlen && !memcmp(field, *exclude, xlen))
 			return 1;
 		exclude++;
 	}
@@ -1357,9 +1356,8 @@ static struct commit_extra_header *read_commit_extra_header_lines(
 		eof = memchr(line, ' ', next - line);
 		if (!eof)
 			eof = next;
-
-		if (standard_header_field(line, eof - line) ||
-		    excluded_header_field(line, eof - line, exclude))
+		else if (standard_header_field(line, eof - line) ||
+			 excluded_header_field(line, eof - line, exclude))
 			continue;
 
 		it = xcalloc(1, sizeof(*it));