Fix strstr and memmem algorithm.

3 files changed, 33 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index faf2befa24..dacd023b73 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-10-05  Eric Blake  <eblake@redhat.com>
+
+	[BZ #12092]
+	* string/str-two-way.h (two_way_long_needle): Always clear memory
+	when skipping input due to the shift table.
+
 2010-10-03  Ulrich Drepper  <drepper@gmail.com>
 
 	[BZ #12005]
diff --git a/string/bug-strstr1.c b/string/bug-strstr1.c
new file mode 100644
index 0000000000..889de12955
--- /dev/null
+++ b/string/bug-strstr1.c
@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <string.h>
+
+int main (int argc, char** argv)
+{
+  const char haystack[] =
+    "F_BD_CE_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_88_20_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_A7_20_EF_BF_BD";
+
+  const char needle[] =
+    "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+
+  const char* sub = strstr (haystack, needle);
+
+  if (sub != NULL)
+    {
+      int j;
+
+      fprintf (stderr, "BUG: expected NULL, got:\n%s\n%s\n", sub, needle);
+      for (j = 0; needle[j] != '\0'; ++j)
+        putchar (needle[j] == sub[j] ? ' ' : '^');
+      puts ("");
+      return 1;
+    }
+
+  return 0;
+}
diff --git a/string/str-two-way.h b/string/str-two-way.h
index 502af47046..76044b34fe 100644
--- a/string/str-two-way.h
+++ b/string/str-two-way.h
@@ -350,8 +350,8 @@ two_way_long_needle (const unsigned char *haystack, size_t haystack_len,
 		     a byte out of place, there can be no match until
 		     after the mismatch.  */
 		  shift = needle_len - period;
-		  memory = 0;
 		}
+	      memory = 0;
 	      j += shift;
 	      continue;
 	    }