1 files changed, 43 insertions, 24 deletions

diff --git a/gl/m4/strstr.m4 b/gl/m4/strstr.m4
index c486bdb0..a32e9c12 100644
--- a/gl/m4/strstr.m4
+++ b/gl/m4/strstr.m4
@@ -1,5 +1,5 @@
-# strstr.m4 serial 16
-dnl Copyright (C) 2008-2013 Free Software Foundation, Inc.
+# strstr.m4 serial 24
+dnl Copyright (C) 2008-2021 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -7,30 +7,40 @@ dnl with or without modifications, as long as this notice is preserved.
 dnl Check that strstr works.
 AC_DEFUN([gl_FUNC_STRSTR_SIMPLE],
 [
-  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  AC_REQUIRE([gl_STRING_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_MEMCHR])
-  if test "$gl_cv_func_memchr_works" != yes; then
+  if test $REPLACE_MEMCHR = 1; then
     REPLACE_STRSTR=1
   else
-    dnl Detect http://sourceware.org/bugzilla/show_bug.cgi?id=12092.
+    dnl Detect https://sourceware.org/bugzilla/show_bug.cgi?id=12092
+    dnl and https://sourceware.org/bugzilla/show_bug.cgi?id=23637.
     AC_CACHE_CHECK([whether strstr works],
       [gl_cv_func_strstr_works_always],
-      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
-#include <string.h> /* for strstr */
+      [AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM([[
+#include <string.h> /* for __GNU_LIBRARY__, strstr */
+#ifdef __GNU_LIBRARY__
+ #include <features.h>
+ #if __GLIBC__ == 2 && __GLIBC_MINOR__ == 28
+  Unlucky user
+ #endif
+#endif
 #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.  uClibc is not
-         dnl affected, since it uses different source code for strstr than
-         dnl glibc.
-         dnl Assume that it works on all other platforms, even if it is not
-         dnl linear.
-         AC_EGREP_CPP([Lucky user],
-           [
+]],
+            [[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.  uClibc is not
+          dnl affected, since it uses different source code for strstr than
+          dnl glibc.
+          dnl Assume that it works on all other platforms, even if it is not
+          dnl linear.
+          AC_EGREP_CPP([Lucky user],
+            [
+#include <string.h> /* for __GNU_LIBRARY__ */
 #ifdef __GNU_LIBRARY__
  #include <features.h>
  #if ((__GLIBC__ == 2 && __GLIBC_MINOR__ > 12) || (__GLIBC__ > 2)) \
@@ -45,10 +55,10 @@ AC_DEFUN([gl_FUNC_STRSTR_SIMPLE],
 #else
   Lucky user
 #endif
-           ],
-           [gl_cv_func_strstr_works_always="guessing yes"],
-           [gl_cv_func_strstr_works_always="guessing no"])
-        ])
+            ],
+            [gl_cv_func_strstr_works_always="guessing yes"],
+            [gl_cv_func_strstr_works_always="$gl_cross_guess_normal"])
+         ])
       ])
     case "$gl_cv_func_strstr_works_always" in
       *yes) ;;
@@ -67,11 +77,17 @@ AC_DEFUN([gl_FUNC_STRSTR],
     AC_CACHE_CHECK([whether strstr works in linear time],
       [gl_cv_func_strstr_linear],
       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#ifdef __MVS__
+/* z/OS does not deliver signals while strstr() is running (thanks to
+   restrictions on its LE runtime), which prevents us from limiting the
+   running time of this test.  */
+# error "This test does not work properly on z/OS"
+#endif
 #include <signal.h> /* for signal */
 #include <string.h> /* for strstr */
 #include <stdlib.h> /* for malloc */
 #include <unistd.h> /* for alarm */
-static void quit (int sig) { exit (sig + 128); }
+static void quit (int sig) { _exit (sig + 128); }
 ]], [[
     int result = 0;
     size_t m = 1000000;
@@ -93,6 +109,9 @@ static void quit (int sig) { exit (sig + 128); }
         if (!strstr (haystack, needle))
           result |= 1;
       }
+    /* Free allocated memory, in case some sanitizer is watching.  */
+    free (haystack);
+    free (needle);
     return result;
     ]])],
         [gl_cv_func_strstr_linear=yes], [gl_cv_func_strstr_linear=no],
@@ -117,7 +136,7 @@ static void quit (int sig) { exit (sig + 128); }
 #endif
            ],
            [gl_cv_func_strstr_linear="guessing yes"],
-           [gl_cv_func_strstr_linear="guessing no"])
+           [gl_cv_func_strstr_linear="$gl_cross_guess_normal"])
         ])
       ])
     case "$gl_cv_func_strstr_linear" in