re PR ada/22255 (Reset on shared file causes Use_Error.)

    gcc/ada/
	PR ada/22255
	* s-fileio.adb (Reset): Do not raise Use_Error if mode isn't changed.

    gcc/testsuite/
	PR ada/22255
	* gnat.dg/test_direct_io.adb: New file.

From-SVN: r132708

gcc/ada/ChangeLog

 2008-02-27  Samuel Tardieu  <sam@rfc1149.net>
 
+	PR ada/22255
+	* s-fileio.adb (Reset): Do not raise Use_Error if mode isn't changed.
+
+2008-02-27  Samuel Tardieu  <sam@rfc1149.net>
+
 	PR ada/34799
 	* sem_ch13.adb (Analyze_Record_Representation_Clause): Check
 	that underlying type is present.

gcc/ada/s-fileio.adb

@@ -1074,13 +1074,15 @@ package body System.File_IO is
    begin
       Check_File_Open (File);
 
-      --  Change of mode not allowed for shared file or file with no name
-      --  or file that is not a regular file, or for a system file.
+      --  Change of mode not allowed for shared file or file with no name or
+      --  file that is not a regular file, or for a system file. Note that we
+      --  allow the "change" of mode if it is not in fact doing a change.
 
-      if File.Shared_Status = Yes
+      if Mode /= File.Mode
+        and then (File.Shared_Status = Yes
                     or else File.Name'Length <= 1
                     or else File.Is_System_File
-        or else not File.Is_Regular_File
+                    or else not File.Is_Regular_File)
       then
          raise Use_Error;
 

gcc/testsuite/ChangeLog

 2008-02-27  Samuel Tardieu  <sam@rfc1149.net>
 
+	PR ada/22255
+	* gnat.dg/test_direct_io.adb: New file.
+
+2008-02-27  Samuel Tardieu  <sam@rfc1149.net>
+
 	PR ada/34799
 	* gnat.dg/specs/pr34799.ads: New test.
 

gcc/testsuite/gnat.dg/test_direct_io.adb

+-- { dg-do run }
+with Ada.Direct_IO;
+
+procedure Test_Direct_IO is
+
+   package BDIO is new Ada.Direct_IO (Boolean);
+   use BDIO;
+
+   FD : File_Type;
+
+begin
+   Create (FD, Form => "shared=yes");
+   Reset (FD);
+   Close (FD);
+end Test_Direct_IO;