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changeset 13772:1d8a613275c6

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memmem, strstr, strcasestr: fix bug with long periodic needle * lib/str-two-way.h (two_way_long_needle): Avoid bug with long periodic needle having false positive. * m4/memmem.m4 (gl_FUNC_MEMMEM_SIMPLE): Detect bug in glibc 2.12 and cygwin 1.7.7. (gl_FUNC_MEMMEM): Be more pessimistic when cross-compiling. * m4/strcasestr.m4 (gl_FUNC_STRCASESTR_SIMPLE) (gl_FUNC_STRCASESTR): Likewise. * m4/strstr.m4 (gl_FUNC_STRSTR_SIMPLE, gl_FUNC_STRSTR): Likewise. * tests/test-memmem.c (main): Expose the bug. * tests/test-strcasestr.c (main): Likewise. * tests/test-strstr.c (main): Likewise. * tests/test-c-strcasestr.c (main): Likewise. * doc/glibc-functions/memmem.texi (memmem): Document the bug. * doc/posix-functions/strstr.texi (strstr): Likewise. * doc/glibc-functions/strcasestr.texi (strcasestr): Likewise. Reported via http://sourceware.org/bugzilla/show_bug.cgi?id=12092 Signed-off-by: Eric Blake <eblake@redhat.com>
author Eric Blake <eblake@redhat.com>
date Tue, 05 Oct 2010 16:39:32 -0600
parents 1d4ace06a1c3
children d06d8f66d2bd
files ChangeLog doc/glibc-functions/memmem.texi doc/glibc-functions/strcasestr.texi doc/posix-functions/strstr.texi lib/str-two-way.h m4/memmem.m4 m4/strcasestr.m4 m4/strstr.m4 tests/test-c-strcasestr.c tests/test-memmem.c tests/test-strcasestr.c tests/test-strstr.c
diffstat 12 files changed, 249 insertions(+), 23 deletions(-) [+]
line wrap: on
line diff
--- a/ChangeLog	Tue Oct 05 15:14:51 2010 -0600
+++ b/ChangeLog	Tue Oct 05 16:39:32 2010 -0600
@@ -1,3 +1,23 @@
+2010-10-05  Eric Blake  <eblake@redhat.com>
+
+	memmem, strstr, strcasestr: fix bug with long periodic needle
+	* lib/str-two-way.h (two_way_long_needle): Avoid bug with long
+	periodic needle having false positive.
+	* m4/memmem.m4 (gl_FUNC_MEMMEM_SIMPLE): Detect bug in glibc 2.12
+	and cygwin 1.7.7.
+	(gl_FUNC_MEMMEM): Be more pessimistic when cross-compiling.
+	* m4/strcasestr.m4 (gl_FUNC_STRCASESTR_SIMPLE)
+	(gl_FUNC_STRCASESTR): Likewise.
+	* m4/strstr.m4 (gl_FUNC_STRSTR_SIMPLE, gl_FUNC_STRSTR): Likewise.
+	* tests/test-memmem.c (main): Expose the bug.
+	* tests/test-strcasestr.c (main): Likewise.
+	* tests/test-strstr.c (main): Likewise.
+	* tests/test-c-strcasestr.c (main): Likewise.
+	* doc/glibc-functions/memmem.texi (memmem): Document the bug.
+	* doc/posix-functions/strstr.texi (strstr): Likewise.
+	* doc/glibc-functions/strcasestr.texi (strcasestr): Likewise.
+	Reported via http://sourceware.org/bugzilla/show_bug.cgi?id=12092
+
 2010-10-05  Paul Eggert  <eggert@cs.ucla.edu>
 
 	parse-datetime: do some more renaming
--- a/doc/glibc-functions/memmem.texi	Tue Oct 05 15:14:51 2010 -0600
+++ b/doc/glibc-functions/memmem.texi	Tue Oct 05 16:39:32 2010 -0600
@@ -13,6 +13,10 @@
 @item
 This function has reversed arguments on some older platforms:
 Linux libc 5.0.9
+@item
+This function can trigger false positives for long periodic needles on
+some platforms:
+glibc 2.12, Cygwin 1.7.7.
 @end itemize
 
 Portability problems fixed by Gnulib module @code{memmem}:
--- a/doc/glibc-functions/strcasestr.texi	Tue Oct 05 15:14:51 2010 -0600
+++ b/doc/glibc-functions/strcasestr.texi	Tue Oct 05 16:39:32 2010 -0600
@@ -15,6 +15,11 @@
 @item
 This function can trigger memchr bugs on some platforms:
 glibc 2.10.
+
+@item
+This function can trigger false positives for long periodic needles on
+some platforms:
+glibc 2.12, Cygwin 1.7.7.
 @end itemize
 
 Portability problems fixed by Gnulib module @code{strcasestr}:
--- a/doc/posix-functions/strstr.texi	Tue Oct 05 15:14:51 2010 -0600
+++ b/doc/posix-functions/strstr.texi	Tue Oct 05 16:39:32 2010 -0600
@@ -12,6 +12,10 @@
 @item
 This function can trigger memchr bugs on some platforms:
 glibc 2.10.
+@item
+This function can trigger false positives for long periodic needles on
+some platforms:
+glibc 2.12, Cygwin 1.7.7.
 @end itemize
 
 Portability problems fixed by Gnulib @code{strstr}:
--- a/lib/str-two-way.h	Tue Oct 05 15:14:51 2010 -0600
+++ b/lib/str-two-way.h	Tue Oct 05 16:39:32 2010 -0600
@@ -370,8 +370,8 @@
                      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;
             }
--- a/m4/memmem.m4	Tue Oct 05 15:14:51 2010 -0600
+++ b/m4/memmem.m4	Tue Oct 05 16:39:32 2010 -0600
@@ -1,4 +1,4 @@
-# memmem.m4 serial 15
+# memmem.m4 serial 16
 dnl Copyright (C) 2002, 2003, 2004, 2007, 2008, 2009, 2010 Free Software
 dnl Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
@@ -16,6 +16,45 @@
   AC_CHECK_DECLS_ONCE([memmem])
   if test $ac_cv_have_decl_memmem = no; then
     HAVE_DECL_MEMMEM=0
+  else
+    dnl Detect http://sourceware.org/bugzilla/show_bug.cgi?id=12092.
+    AC_CACHE_CHECK([whether memmem works],
+      [gl_cv_func_memmem_works_always],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <string.h> /* for memmem */
+#define P "_EF_BF_BD"
+#define HAYSTACK "F_BD_CE_BD" P P P P "_C3_88_20" P P P "_C3_A7_20" P
+#define NEEDLE P P P P P
+]], [[return !!memmem (HAYSTACK, strlen (HAYSTACK), NEEDLE, strlen (NEEDLE));
+    ]])],
+        [gl_cv_func_memmem_works_always=yes],
+        [gl_cv_func_memmem_works_always=no],
+        [dnl glibc 2.12 and cygwin 1.7.7 have a known bug.  Assume that it
+         dnl works on all other platforms, even if it is not linear.
+         AC_EGREP_CPP([Lucky user],
+           [
+#ifdef __GNU_LIBRARY__
+ #include <features.h>
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)
+  Lucky user
+ #endif
+#elif defined __CYGWIN__
+ #include <cygwin/version.h>
+ #if CYGWIN_VERSION_DLL_MAJOR >= 1007 && CYGWIN_VERSION_DLL_MINOR > 7
+  Lucky user
+ #endif
+#else
+  Lucky user
+#endif
+           ],
+           [gl_cv_func_memmem_works_always=yes],
+           [gl_cv_func_memmem_works_always="guessing no"])
+        ])
+      ])
+    if test "$gl_cv_func_memmem_works_always" != yes; then
+      REPLACE_MEMMEM=1
+      AC_LIBOBJ([memmem])
+    fi
   fi
   gl_PREREQ_MEMMEM
 ]) # gl_FUNC_MEMMEM_SIMPLE
@@ -24,9 +63,9 @@
 AC_DEFUN([gl_FUNC_MEMMEM],
 [
   AC_REQUIRE([gl_FUNC_MEMMEM_SIMPLE])
-  if test $ac_cv_have_decl_memmem = yes; then
+  if test $HAVE_MEMMEM = 1 && test $REPLACE_MEMMEM = 0; then
     AC_CACHE_CHECK([whether memmem works in linear time],
-      [gl_cv_func_memmem_works],
+      [gl_cv_func_memmem_works_fast],
       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
 #include <signal.h> /* for signal */
 #include <string.h> /* for memmem */
@@ -52,29 +91,29 @@
       }
     /* Check for empty needle behavior.  */
     return !result || !memmem ("a", 1, 0, 0);]])],
-        [gl_cv_func_memmem_works=yes], [gl_cv_func_memmem_works=no],
-        [dnl Only glibc >= 2.9 and cygwin >= 1.7.0 are known to have a
-         dnl memmem that works in linear time.
+        [gl_cv_func_memmem_works_fast=yes], [gl_cv_func_memmem_works_fast=no],
+        [dnl Only glibc > 2.12 and cygwin > 1.7.7 are known to have a
+         dnl bug-free memmem that works in linear time.
          AC_EGREP_CPP([Lucky user],
            [
 #include <features.h>
 #ifdef __GNU_LIBRARY__
- #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 9) || (__GLIBC__ > 2)
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)
   Lucky user
  #endif
 #endif
 #ifdef __CYGWIN__
  #include <cygwin/version.h>
- #if CYGWIN_VERSION_DLL_MAJOR >= 1007
+ #if CYGWIN_VERSION_DLL_MAJOR >= 1007 && CYGWIN_VERSION_DLL_MINOR > 7
   Lucky user
  #endif
 #endif
            ],
-           [gl_cv_func_memmem_works=yes],
-           [gl_cv_func_memmem_works="guessing no"])
+           [gl_cv_func_memmem_works_fast=yes],
+           [gl_cv_func_memmem_works_fast="guessing no"])
         ])
       ])
-    if test "$gl_cv_func_memmem_works" != yes; then
+    if test "$gl_cv_func_memmem_works_fast" != yes; then
       REPLACE_MEMMEM=1
       AC_LIBOBJ([memmem])
     fi
--- a/m4/strcasestr.m4	Tue Oct 05 15:14:51 2010 -0600
+++ b/m4/strcasestr.m4	Tue Oct 05 16:39:32 2010 -0600
@@ -1,4 +1,4 @@
-# strcasestr.m4 serial 14
+# strcasestr.m4 serial 15
 dnl Copyright (C) 2005, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -19,6 +19,45 @@
   else
     if test "$gl_cv_func_memchr_works" != yes; then
       REPLACE_STRCASESTR=1
+    else
+      dnl Detect http://sourceware.org/bugzilla/show_bug.cgi?id=12092.
+      AC_CACHE_CHECK([whether strcasestr works],
+        [gl_cv_func_strcasestr_works_always],
+        [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <string.h> /* for strcasestr */
+#define P "_EF_BF_BD"
+#define HAYSTACK "F_BD_CE_BD" P P P P "_C3_88_20" P P P "_C3_A7_20" P
+#define NEEDLE P P P P P
+]], [[return !!strcasestr (HAYSTACK, NEEDLE);
+      ]])],
+          [gl_cv_func_strcasestr_works_always=yes],
+          [gl_cv_func_strcasestr_works_always=no],
+          [dnl glibc 2.12 and cygwin 1.7.7 have a known bug.  Assume that it
+           dnl works on all other platforms, even if it is not linear.
+           AC_EGREP_CPP([Lucky user],
+             [
+#ifdef __GNU_LIBRARY__
+ #include <features.h>
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)
+  Lucky user
+ #endif
+#elif defined __CYGWIN__
+ #include <cygwin/version.h>
+ #if CYGWIN_VERSION_DLL_MAJOR >= 1007 && CYGWIN_VERSION_DLL_MINOR > 7
+  Lucky user
+ #endif
+#else
+  Lucky user
+#endif
+             ],
+             [gl_cv_func_strcasestr_works_always=yes],
+             [gl_cv_func_strcasestr_works_always="guessing no"])
+          ])
+        ])
+      if test "$gl_cv_func_strcasestr_works_always" != yes; then
+        REPLACE_STRCASESTR=1
+        AC_LIBOBJ([strcasestr])
+      fi
     fi
   fi
   if test $HAVE_STRCASESTR = 0 || test $REPLACE_STRCASESTR = 1; then
@@ -36,7 +75,7 @@
       [gl_cv_func_strcasestr_linear],
       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
 #include <signal.h> /* for signal */
-#include <string.h> /* for memmem */
+#include <string.h> /* for strcasestr */
 #include <stdlib.h> /* for malloc */
 #include <unistd.h> /* for alarm */
 static void quit (int sig) { exit (sig + 128); }
@@ -61,19 +100,19 @@
       }
     return !result;]])],
         [gl_cv_func_strcasestr_linear=yes], [gl_cv_func_strcasestr_linear=no],
-        [dnl Only glibc >= 2.9 and cygwin >= 1.7.0 are known to have a
+        [dnl Only glibc > 2.12 and cygwin > 1.7.7 are known to have a
          dnl strcasestr that works in linear time.
          AC_EGREP_CPP([Lucky user],
            [
 #include <features.h>
 #ifdef __GNU_LIBRARY__
- #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 9) || (__GLIBC__ > 2)
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)
   Lucky user
  #endif
 #endif
 #ifdef __CYGWIN__
  #include <cygwin/version.h>
- #if CYGWIN_VERSION_DLL_MAJOR >= 1007
+ #if CYGWIN_VERSION_DLL_MAJOR >= 1007 && CYGWIN_VERSION_DLL_MINOR > 7
   Lucky user
  #endif
 #endif
--- a/m4/strstr.m4	Tue Oct 05 15:14:51 2010 -0600
+++ b/m4/strstr.m4	Tue Oct 05 16:39:32 2010 -0600
@@ -1,4 +1,4 @@
-# strstr.m4 serial 8
+# strstr.m4 serial 9
 dnl Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -12,6 +12,45 @@
   if test "$gl_cv_func_memchr_works" != yes; then
     REPLACE_STRSTR=1
     AC_LIBOBJ([strstr])
+  else
+    dnl Detect http://sourceware.org/bugzilla/show_bug.cgi?id=12092.
+    AC_CACHE_CHECK([whether strstr works],
+      [gl_cv_func_strstr_works_always],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <string.h> /* for strstr */
+#define P "_EF_BF_BD"
+#define HAYSTACK "F_BD_CE_BD" P P P P "_C3_88_20" P P P "_C3_A7_20" P
+#define NEEDLE P P P P P
+]], [[return !!strstr (HAYSTACK, NEEDLE);
+    ]])],
+        [gl_cv_func_strstr_works_always=yes],
+        [gl_cv_func_strstr_works_always=no],
+        [dnl glibc 2.12 and cygwin 1.7.7 have a known bug.  Assume that it
+         dnl works on all other platforms, even if it is not linear.
+         AC_EGREP_CPP([Lucky user],
+           [
+#ifdef __GNU_LIBRARY__
+ #include <features.h>
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)
+  Lucky user
+ #endif
+#elif defined __CYGWIN__
+ #include <cygwin/version.h>
+ #if CYGWIN_VERSION_DLL_MAJOR >= 1007 && CYGWIN_VERSION_DLL_MINOR > 7
+  Lucky user
+ #endif
+#else
+  Lucky user
+#endif
+           ],
+           [gl_cv_func_strstr_works_always=yes],
+           [gl_cv_func_strstr_works_always="guessing no"])
+        ])
+      ])
+    if test "$gl_cv_func_strstr_works_always" != yes; then
+      REPLACE_STRSTR=1
+      AC_LIBOBJ([strstr])
+    fi
   fi
 ]) # gl_FUNC_STRSTR_SIMPLE
 
@@ -24,7 +63,7 @@
       [gl_cv_func_strstr_linear],
       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
 #include <signal.h> /* for signal */
-#include <string.h> /* for memmem */
+#include <string.h> /* for strstr */
 #include <stdlib.h> /* for malloc */
 #include <unistd.h> /* for alarm */
 static void quit (int sig) { exit (sig + 128); }
@@ -49,19 +88,19 @@
       }
     return !result;]])],
         [gl_cv_func_strstr_linear=yes], [gl_cv_func_strstr_linear=no],
-        [dnl Only glibc >= 2.9 and cygwin >= 1.7.0 are known to have a
-         dnl strstr that works in linear time.
+        [dnl Only glibc > 2.12 and cygwin > 1.7.7 are known to have a
+         dnl bug-free strstr that works in linear time.
          AC_EGREP_CPP([Lucky user],
            [
 #include <features.h>
 #ifdef __GNU_LIBRARY__
- #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 9) || (__GLIBC__ > 2)
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)
   Lucky user
  #endif
 #endif
 #ifdef __CYGWIN__
  #include <cygwin/version.h>
- #if CYGWIN_VERSION_DLL_MAJOR >= 1007
+ #if CYGWIN_VERSION_DLL_MAJOR >= 1007 && CYGWIN_VERSION_DLL_MINOR > 7
   Lucky user
  #endif
 #endif
--- a/tests/test-c-strcasestr.c	Tue Oct 05 15:14:51 2010 -0600
+++ b/tests/test-c-strcasestr.c	Tue Oct 05 16:39:32 2010 -0600
@@ -58,6 +58,25 @@
     ASSERT (result == input + 11);
   }
 
+  /* Check that a long periodic needle does not cause false positives.  */
+  {
+    const char input[] = ("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 need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+    const char *result = c_strcasestr (input, need);
+    ASSERT (result == NULL);
+  }
+  {
+    const char input[] = ("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_DA_B5_C2_A6_20"
+                          "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD");
+    const char need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+    const char *result = c_strcasestr (input, need);
+    ASSERT (result == input + 115);
+  }
+
   /* Check that a very long haystack is handled quickly if the needle is
      short and occurs near the beginning.  */
   {
--- a/tests/test-memmem.c	Tue Oct 05 15:14:51 2010 -0600
+++ b/tests/test-memmem.c	Tue Oct 05 16:39:32 2010 -0600
@@ -89,6 +89,25 @@
     ASSERT (result == input);
   }
 
+  /* Check that a long periodic needle does not cause false positives.  */
+  {
+    const char input[] = ("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 need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+    const char *result = memmem (input, strlen (input), need, strlen (need));
+    ASSERT (result == NULL);
+  }
+  {
+    const char input[] = ("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_DA_B5_C2_A6_20"
+                          "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD");
+    const char need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+    const char *result = memmem (input, strlen (input), need, strlen (need));
+    ASSERT (result == input + 115);
+  }
+
   /* Check that a very long haystack is handled quickly if the needle is
      short and occurs near the beginning.  */
   {
--- a/tests/test-strcasestr.c	Tue Oct 05 15:14:51 2010 -0600
+++ b/tests/test-strcasestr.c	Tue Oct 05 16:39:32 2010 -0600
@@ -71,6 +71,25 @@
     ASSERT (result == input + 11);
   }
 
+  /* Check that a long periodic needle does not cause false positives.  */
+  {
+    const char input[] = ("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 need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+    const char *result = strcasestr (input, need);
+    ASSERT (result == NULL);
+  }
+  {
+    const char input[] = ("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_DA_B5_C2_A6_20"
+                          "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD");
+    const char need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+    const char *result = strcasestr (input, need);
+    ASSERT (result == input + 115);
+  }
+
   /* Check that a very long haystack is handled quickly if the needle is
      short and occurs near the beginning.  */
   {
--- a/tests/test-strstr.c	Tue Oct 05 15:14:51 2010 -0600
+++ b/tests/test-strstr.c	Tue Oct 05 16:39:32 2010 -0600
@@ -91,6 +91,25 @@
     ASSERT (result == input + 11);
   }
 
+  /* Check that a long periodic needle does not cause false positives.  */
+  {
+    const char input[] = ("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 need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+    const char *result = strstr (input, need);
+    ASSERT (result == NULL);
+  }
+  {
+    const char input[] = ("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_DA_B5_C2_A6_20"
+                          "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD");
+    const char need[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+    const char *result = strstr (input, need);
+    ASSERT (result == input + 115);
+  }
+
   /* Check that a very long haystack is handled quickly if the needle is
      short and occurs near the beginning.  */
   {