grep: fix segfault when "git grep '('" is given

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/grep.c b/grep.c
index 13c18ff6529f437e6aea2671ab0003d4fd047ac7..a4edacad8b4e4365bc22266521e26f3b617d53b5 100644 (file)
--- a/grep.c
+++ b/grep.c
@@ -54,6 +54,8 @@ static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
        struct grep_expr *x;
 
        p = *list;
+       if (!p)
+               return NULL;
        switch (p->token) {
        case GREP_PATTERN: /* atom */
        case GREP_PATTERN_HEAD:
@@ -66,8 +68,6 @@ static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
        case GREP_OPEN_PAREN:
                *list = p->next;
                x = compile_pattern_or(list);
-               if (!x)
-                       return NULL;
                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
                        die("unmatched parenthesis");
                *list = (*list)->next;
@@ -83,6 +83,8 @@ static struct grep_expr *compile_pattern_not(struct grep_pat **list)
        struct grep_expr *x;
 
        p = *list;
+       if (!p)
+               return NULL;
        switch (p->token) {
        case GREP_NOT:
                if (!p->next)
@@ -361,6 +363,8 @@ static int match_expr_eval(struct grep_opt *o,
 {
        int h = 0;
 
+       if (!x)
+               die("Not a valid grep expression");
        switch (x->node) {
        case GREP_NODE_ATOM:
                h = match_one_pattern(o, x->u.atom, bol, eol, ctx);

diff --git a/t/t7002-grep.sh b/t/t7002-grep.sh
index 5e359cb561b6d6f7c1bae678b7b823ed2ce34cf1..087bacb89747bb3da7fc3f7ab3fe08bacea91d52 100755 (executable)
--- a/t/t7002-grep.sh
+++ b/t/t7002-grep.sh
@@ -26,6 +26,10 @@ test_expect_success setup '
        git commit -m initial
 '
 
+test_expect_success 'grep should not segfault with a bad input' '
+       test_must_fail git grep "("
+'
+
 for H in HEAD ''
 do
        case "$H" in