attr.c: plug small leak in parse_attr_line()

If any error is noticed after the match_attr structure is allocated,
we shouldn't just return NULL from this function.

Add a fail_return label that frees the allocated structure and
returns NULL, and consistently jump there when we want to return
NULL after cleaning up.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/attr.c b/attr.c
index f7cf7ae3060fc401fe3a2c4c44c24c32915d4601..d180c7833e363bd41aacf6785a20dafc3603bf7d 100644 (file)
--- a/attr.c
+++ b/attr.c
@@ -223,7 +223,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
                if (!macro_ok) {
                        fprintf(stderr, "%s not allowed: %s:%d\n",
                                name, src, lineno);
-                       return NULL;
+                       goto fail_return;
                }
                is_macro = 1;
                name += strlen(ATTRIBUTE_MACRO_PREFIX);
@@ -233,7 +233,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
                        fprintf(stderr,
                                "%.*s is not a valid attribute name: %s:%d\n",
                                namelen, name, src, lineno);
-                       return NULL;
+                       goto fail_return;
                }
        }
        else
@@ -246,7 +246,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
        for (cp = states, num_attr = 0; *cp; num_attr++) {
                cp = parse_attr(src, lineno, cp, NULL);
                if (!cp)
-                       return NULL;
+                       goto fail_return;
        }
 
        res = xcalloc(1,
@@ -267,7 +267,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
                if (res->u.pat.flags & EXC_FLAG_NEGATIVE) {
                        warning(_("Negative patterns are ignored in git attributes\n"
                                  "Use '\\!' for literal leading exclamation."));
-                       return NULL;
+                       goto fail_return;
                }
        }
        res->is_macro = is_macro;
@@ -283,6 +283,10 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
        }
 
        return res;
+
+fail_return:
+       free(res);
+       return NULL;
 }
 
 /*