From patchwork Thu Jun  7 14:35:41 2012
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Subject: [fortran,committed] Fix regression introduced by PR 52861 patch
Date: Thu, 07 Jun 2012 04:35:41 -0000
From: Thomas Koenig <tkoenig@netcologne.de>
X-Patchwork-Id: 163638
Message-Id: <4FD0BC3D.7070606@netcologne.de>
To: "fortran@gcc.gnu.org" <fortran@gcc.gnu.org>,
 gcc-patches <gcc-patches@gcc.gnu.org>

Hello world,

my recent patch introduced a regression with deferred-length
characters.  I have committed the attached patch as obvious
to fix this.

Regards

	Thomas

2012-06-07  Thomas König  <tkoenig@gcc.gnu.org>

         PR fortran/52861
         * frontend-passes.c (optimize_assignment):  Don't set the
         length of an empty string for deferred-length character
         variables.

2012-06-07  Thomas König  <tkoenig@gcc.gnu.org>

         PR fortran/52861
         * gfortran.dg/string_assign_2.f90:  New test case.


Index: frontend-passes.c
===================================================================
--- frontend-passes.c	(Revision 188300)
+++ frontend-passes.c	(Arbeitskopie)
@@ -740,8 +740,10 @@ optimize_assignment (gfc_code * c)
       /* Optimize away a = trim(b), where a is a character variable.  */
       remove_trim (rhs);
 
-      /* Replace a = '   ' by a = '' to optimize away a memcpy.  */
-      if (empty_string(rhs))
+      /* Replace a = '   ' by a = '' to optimize away a memcpy, but only
+	 for strings with non-deferred length (otherwise we would
+	 reallocate the length.  */
+      if (empty_string(rhs) && ! lhs->ts.deferred)
 	rhs->value.character.length = 0;
     }