X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=m4%2Ffflush.m4;h=9098b100a5121fec831a5bd504b9199fd2b73064;hb=893a617c579911c9a56018fd7b63703ee3c13ff8;hp=6df51736812529ac17c0a223d1b4a535fd1a9745;hpb=d57728a6ca2413a7c564d8b7bb13d9e5a5a180f3;p=debian%2Fgzip

diff --git a/m4/fflush.m4 b/m4/fflush.m4
index 6df5173..9098b10 100644
--- a/m4/fflush.m4
+++ b/m4/fflush.m4
@@ -1,6 +1,6 @@
-# fflush.m4 serial 14
+# fflush.m4 serial 17
 
-# Copyright (C) 2007-2013 Free Software Foundation, Inc.
+# Copyright (C) 2007-2018 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.
@@ -14,9 +14,10 @@ AC_DEFUN([gl_FUNC_FFLUSH],
 [
   AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   gl_FUNC_FFLUSH_STDIN
-  if test $gl_cv_func_fflush_stdin = no; then
-    REPLACE_FFLUSH=1
-  fi
+  case "$gl_cv_func_fflush_stdin" in
+    *yes) ;;
+    *) REPLACE_FFLUSH=1 ;;
+  esac
 ])
 
 dnl Determine whether fflush works on input streams.
@@ -24,6 +25,7 @@ dnl Sets gl_cv_func_fflush_stdin.
 
 AC_DEFUN([gl_FUNC_FFLUSH_STDIN],
 [
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CHECK_HEADERS_ONCE([unistd.h])
   AC_CACHE_CHECK([whether fflush works on input streams],
     [gl_cv_func_fflush_stdin],
@@ -44,16 +46,16 @@ AC_DEFUN([gl_FUNC_FFLUSH_STDIN],
            return 1;
          fd = fileno (f);
          if (fd < 0 || fread (buffer, 1, 5, f) != 5)
-           return 2;
+           { fclose (f); return 2; }
          /* For deterministic results, ensure f read a bigger buffer.  */
          if (lseek (fd, 0, SEEK_CUR) == 5)
-           return 3;
+           { fclose (f); return 3; }
          /* POSIX requires fflush-fseek to set file offset of fd.  This fails
             on BSD systems and on mingw.  */
          if (fflush (f) != 0 || fseek (f, 0, SEEK_CUR) != 0)
-           return 4;
+           { fclose (f); return 4; }
          if (lseek (fd, 0, SEEK_CUR) != 5)
-           return 5;
+           { fclose (f); return 5; }
          /* Verify behaviour of fflush after ungetc. See
             <http://www.opengroup.org/austin/aardvark/latest/xshbug3.txt>  */
          /* Verify behaviour of fflush after a backup ungetc.  This fails on
@@ -62,20 +64,35 @@ AC_DEFUN([gl_FUNC_FFLUSH_STDIN],
          ungetc (c, f);
          fflush (f);
          if (fgetc (f) != c)
-           return 6;
+           { fclose (f); return 6; }
          /* Verify behaviour of fflush after a non-backup ungetc.  This fails
             on glibc 2.8 and on BSD systems.  */
          c = fgetc (f);
          ungetc ('@', f);
          fflush (f);
          if (fgetc (f) != c)
-           return 7;
+           { fclose (f); return 7; }
+         fclose (f);
          return 0;
-       ]])], [gl_cv_func_fflush_stdin=yes], [gl_cv_func_fflush_stdin=no],
-     [dnl Pessimistically assume fflush is broken.
-      gl_cv_func_fflush_stdin=no])
+       ]])],
+       [gl_cv_func_fflush_stdin=yes],
+       [gl_cv_func_fflush_stdin=no],
+       [case "$host_os" in
+                  # Guess no on native Windows.
+          mingw*) gl_cv_func_fflush_stdin="guessing no" ;;
+          *)      gl_cv_func_fflush_stdin=cross ;;
+        esac
+       ])
      rm conftest.txt
     ])
+  case "$gl_cv_func_fflush_stdin" in
+    *yes) gl_func_fflush_stdin=1 ;;
+    *no)  gl_func_fflush_stdin=0 ;;
+    *)    gl_func_fflush_stdin='(-1)' ;;
+  esac
+  AC_DEFINE_UNQUOTED([FUNC_FFLUSH_STDIN], [$gl_func_fflush_stdin],
+    [Define to 1 if fflush is known to work on stdin as per POSIX.1-2008,
+     0 if fflush is known to not work, -1 if unknown.])
 ])
 
 # Prerequisites of lib/fflush.c.