grep: handle corrupt index files early

diff --git a/sha1_file.c b/sha1_file.c
index 10c3a0083dedee98dc3d48267ad349589adef3f0..36f85455e6748efb7c2d593c7a619fa13150600b 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -404,6 +404,9 @@ static void link_alt_odb_entries(const char *alt, int sep,
        struct strbuf objdirbuf = STRBUF_INIT;
        struct strbuf entry = STRBUF_INIT;
 
+       if (!alt || !*alt)
+               return;
+
        if (depth > 5) {
                error("%s: ignoring alternate object stores, nesting too deep.",
                                relative_base);
@@ -607,7 +610,6 @@ void prepare_alt_odb(void)
                return;
 
        alt = getenv(ALTERNATE_DB_ENVIRONMENT);
-       if (!alt) alt = "";
 
        alt_odb_tail = &alt_odb_list;
        link_alt_odb_entries(alt, PATH_SEP, NULL, 0);