Fix grep bug where -f /dev/null added "" regex matching everything,

and address TODO where -z was still splitting patterns on \n

1 files changed, 15 insertions, 11 deletions

diff --git a/toys/posix/grep.c b/toys/posix/grep.c
index fce8d564..2ddb6b93 100644
--- a/toys/posix/grep.c
+++ b/toys/posix/grep.c
@@ -372,13 +372,24 @@ static void parse_regex(void)
   // exit to free. Not supporting nofork for this command any time soon.)
   al = TT.f ? TT.f : TT.e;
   while (al) {
-    if (TT.f) s = ss = xreadfile(al->arg, 0, 0);
-    else s = ss = al->arg;
+    if (TT.f) {
+      if (!*(s = ss = xreadfile(al->arg, 0, 0))) {
+        free(ss);
+        s = 0;
+      }
+    } else s = ss = al->arg;
+
+    // Advance, when we run out of -f switch to -e.
+    al = al->next;
+    if (!al && TT.f) {
+      TT.f = 0;
+      al = TT.e;
+    }
+    if (!s) continue;
 
     // Split lines at \n, add individual lines to new list.
     do {
-// TODO: NUL terminated input shouldn't split -e at \n
-      ss = strchr(s, '\n');
+      ss = FLAG(z) ? 0 : strchr(s, '\n');
       if (ss) *(ss++) = 0;
       new = xmalloc(sizeof(struct arg_list));
       new->next = list;
@@ -386,13 +397,6 @@ static void parse_regex(void)
       list = new;
       s = ss;
     } while (ss && *s);
-
-    // Advance, when we run out of -f switch to -e.
-    al = al->next;
-    if (!al && TT.f) {
-      TT.f = 0;
-      al = TT.e;
-    }
   }
   TT.e = list;