Patch for fortran/62536 and fortran/66175

[Louis Krupp]

This patch cleans up nested blocks when there's an unexpected end of a 
compilation unit (66175), and it handles cleaned-up blocks gracefully (62536).  
I've run "make check-fortran" with the attached test cases.

Index: ChangeLog
===================================================================
--- ChangeLog   (revision 226452)
+++ ChangeLog   (working copy)
@@ -1877,6 +1877,13 @@
        * interface.c (is_procptr_result): New function to check if an
        expression is a procedure-pointer result.
        (compare_actual_formal): Use it.
+
+2015_07_31  Louis Krupp <louis.kr...@zoho.com>
+
+    PR fortran/62536 and fortran/66175
+       * decl.c (gfc_match_end): Clean up nested BLOCKs.
+       * parse.c (parse_block_construct): Deal gracefully with cleaned-up
+       BLOCKs.
 ^L
 Copyright (C) 2015 Free Software Foundation, Inc.
 
Index: decl.c
===================================================================
--- decl.c      (revision 226452)
+++ decl.c      (working copy)
@@ -6483,7 +6483,7 @@ cleanup:
   /* If we are missing an END BLOCK, we created a half-ready namespace.
      Remove it from the parent namespace's sibling list.  */
 
-  if (state == COMP_BLOCK)
+  while (state == COMP_BLOCK)
     {
       parent_ns = gfc_current_ns->parent;
 
@@ -6506,6 +6506,8 @@ cleanup:
   
       gfc_free_namespace (gfc_current_ns);
       gfc_current_ns = parent_ns;
+      gfc_state_stack = gfc_state_stack->previous;
+      state = gfc_current_state ();
     }
 
   return MATCH_ERROR;
Index: parse.c
===================================================================
--- parse.c     (revision 226452)
+++ parse.c     (working copy)
@@ -3935,6 +3935,7 @@ static void
 parse_block_construct (void)
 {
   gfc_namespace* my_ns;
+  gfc_namespace* my_parent;
   gfc_state_data s;
 
   gfc_notify_std (GFC_STD_F2008, "BLOCK construct at %C");
@@ -3948,10 +3949,15 @@ parse_block_construct (void)
 
   push_state (&s, COMP_BLOCK, my_ns->proc_name);
   gfc_current_ns = my_ns;
+  my_parent = my_ns->parent;
 
   parse_progunit (ST_NONE);
 
-  gfc_current_ns = gfc_current_ns->parent;
+  /*
+   * Don't depend on the value of gfc_current_ns;  it might have been
+   * reset if the block had errors and was cleaned up.
+   */
+  gfc_current_ns = my_parent;
   pop_state ();
 }

blocks_nested_incomplete_1.f90
Description: Binary data

block_end_error_1.f90
Description: Binary data