Ensure that HAVE_* variables are set to 1 before they are set to 0.

[gnulib.git] / m4 / getcwd-abort-bug.m4

diff --git a/m4/getcwd-abort-bug.m4 b/m4/getcwd-abort-bug.m4
index f15181f..60ea03c 100644 (file)
--- a/m4/getcwd-abort-bug.m4
+++ b/m4/getcwd-abort-bug.m4
@@ -1,4 +1,4 @@
-# serial 3
+# serial 6
 # Determine whether getcwd aborts when the length of the working directory
 # name is unusually large.  Any length between 4k and 16k trigger the bug
 # when using glibc-2.4.90-9 or older.
@@ -14,6 +14,8 @@
 AC_DEFUN([gl_FUNC_GETCWD_ABORT_BUG],
 [
   AC_CHECK_DECLS_ONCE([getcwd])
+  AC_CHECK_HEADERS_ONCE([unistd.h])
+  AC_REQUIRE([gl_PATHMAX_SNIPPET_PREREQ])
   AC_CHECK_FUNCS([getpagesize])
   AC_CACHE_CHECK([whether getcwd aborts when 4k < cwd_length < 16k],
     gl_cv_func_getcwd_abort_bug,
@@ -21,15 +23,21 @@ AC_DEFUN([gl_FUNC_GETCWD_ABORT_BUG],
      rm -rf confdir-14B---
      # Arrange for deletion of the temporary directory this test creates.
      ac_clean_files="$ac_clean_files confdir-14B---"
+     dnl Please keep this in sync with tests/test-getcwd.c.
      AC_RUN_IFELSE(
        [AC_LANG_SOURCE(
           [[
 #include <stdlib.h>
-#include <unistd.h>
-#include <limits.h>
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#else /* on Windows with MSVC */
+# include <direct.h>
+#endif
 #include <string.h>
 #include <sys/stat.h>
 
+]gl_PATHMAX_SNIPPET[
+
 /* Don't get link errors because mkdir is redefined to rpl_mkdir.  */
 #undef mkdir
 
@@ -64,7 +72,7 @@ main ()
 
   cwd = getcwd (NULL, 0);
   if (cwd == NULL)
-    return 0;
+    return 2;
 
   initial_cwd_len = strlen (cwd);
   free (cwd);
@@ -91,15 +99,22 @@ main ()
   while (0 < d--)
     {
       if (chdir ("..") < 0)
-        break;
+        {
+          fail = 5;
+          break;
+        }
       rmdir (dir_name);
     }
 
-  return 0;
+  return fail;
 }
           ]])],
     [gl_cv_func_getcwd_abort_bug=no],
-    [gl_cv_func_getcwd_abort_bug=yes],
+    dnl A "regular" nonzero return does not indicate this bug.
+    dnl An abort will provoke an exit code of something like 134 (128 + 6).
+    [test $? -gt 128 \
+      && gl_cv_func_getcwd_abort_bug=yes \
+      || gl_cv_func_getcwd_abort_bug=no],
     [gl_cv_func_getcwd_abort_bug=yes])
   ])
   AS_IF([test $gl_cv_func_getcwd_abort_bug = yes], [$1], [$2])