mkstemp: replace if system version uses wrong permissions

[gnulib.git] / m4 / mkstemp.m4

diff --git a/m4/mkstemp.m4 b/m4/mkstemp.m4
index 6544f1a..06187c6 100644 (file)
--- a/m4/mkstemp.m4
+++ b/m4/mkstemp.m4
@@ -1,6 +1,6 @@
-#serial 17
+#serial 20
 
-# Copyright (C) 2001, 2003-2007, 2009 Free Software Foundation, Inc.
+# Copyright (C) 2001, 2003-2007, 2009-2011 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
@@ -10,41 +10,62 @@
 # Other systems lack mkstemp altogether.
 # On OSF1/Tru64 V4.0F, the system-provided mkstemp function can create
 # only 32 files per process.
+# On some hosts, mkstemp creates files with mode 0666, which is a security
+# problem and a violation of POSIX 2008.
 # On systems like the above, arrange to use the replacement function.
 AC_DEFUN([gl_FUNC_MKSTEMP],
 [
   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
   AC_REQUIRE([AC_SYS_LARGEFILE])
 
-  AC_CACHE_CHECK([for working mkstemp],
-    [gl_cv_func_working_mkstemp],
-    [
-      mkdir conftest.mkstemp
-      AC_RUN_IFELSE(
-        [AC_LANG_PROGRAM(
-          [AC_INCLUDES_DEFAULT],
-          [[int i;
-            off_t large = (off_t) 4294967295u;
-            if (large < 0)
-              large = 2147483647;
-            for (i = 0; i < 70; i++)
-              {
-                char templ[] = "conftest.mkstemp/coXXXXXX";
-                int (*mkstemp_function) (char *) = mkstemp;
-                int fd = mkstemp_function (templ);
-                if (fd < 0 || lseek (fd, large, SEEK_SET) != large)
-                  return 1;
-                close (fd);
-              }
-            return 0;]])],
-        [gl_cv_func_working_mkstemp=yes],
-        [gl_cv_func_working_mkstemp=no],
-        [gl_cv_func_working_mkstemp=no])
-      rm -rf conftest.mkstemp
-    ])
-
-  if test $gl_cv_func_working_mkstemp != yes; then
-    REPLACE_MKSTEMP=1
+  AC_CHECK_FUNCS_ONCE([mkstemp])
+  if test $ac_cv_func_mkstemp = yes; then
+    AC_CACHE_CHECK([for working mkstemp],
+      [gl_cv_func_working_mkstemp],
+      [
+        mkdir conftest.mkstemp
+        AC_RUN_IFELSE(
+          [AC_LANG_PROGRAM(
+            [AC_INCLUDES_DEFAULT],
+            [[int result = 0;
+              int i;
+              off_t large = (off_t) 4294967295u;
+              if (large < 0)
+                large = 2147483647;
+              umask (0);
+              for (i = 0; i < 70; i++)
+                {
+                  char templ[] = "conftest.mkstemp/coXXXXXX";
+                  int (*mkstemp_function) (char *) = mkstemp;
+                  int fd = mkstemp_function (templ);
+                  if (fd < 0)
+                    result |= 1;
+                  else
+                    {
+                      struct stat st;
+                      if (lseek (fd, large, SEEK_SET) != large)
+                        result |= 2;
+                      if (fstat (fd, &st) < 0)
+                        result |= 4;
+                      else if (st.st_mode & 0077)
+                        result |= 8;
+                      if (close (fd))
+                        result |= 16;
+                    }
+                }
+              return result;]])],
+          [gl_cv_func_working_mkstemp=yes],
+          [gl_cv_func_working_mkstemp=no],
+          [gl_cv_func_working_mkstemp=no])
+        rm -rf conftest.mkstemp
+      ])
+    if test $gl_cv_func_working_mkstemp != yes; then
+      REPLACE_MKSTEMP=1
+      AC_LIBOBJ([mkstemp])
+      gl_PREREQ_MKSTEMP
+    fi
+  else
+    HAVE_MKSTEMP=0
     AC_LIBOBJ([mkstemp])
     gl_PREREQ_MKSTEMP
   fi