Index: gcc/testsuite/gfortran.dg/maxerrors.f90
===================================================================
--- gcc/testsuite/gfortran.dg/maxerrors.f90	(revision 0)
+++ gcc/testsuite/gfortran.dg/maxerrors.f90	(revision 0)
@@ -0,0 +1,12 @@
+! { dg-do compile }
+! { dg-options "-fmax-errors=1" }
+! PR66528
+! { dg-prune-output "compilation terminated" }
+program main
+  read (*,*) n
+  if (n<0) then
+    print *,foo
+  end ! { dg-error "END IF statement expected" }
+    print *,bar
+end program main
+
Index: gcc/fortran/error.c
===================================================================
--- gcc/fortran/error.c	(revision 224844)
+++ gcc/fortran/error.c	(working copy)
@@ -1247,24 +1247,23 @@ gfc_clear_warning (void)
    If so, print the warning.  */
 
 void
 gfc_warning_check (void)
 {
-  /* This is for the new diagnostics machinery.  */
   if (! gfc_output_buffer_empty_p (pp_warning_buffer))
     {
       pretty_printer *pp = global_dc->printer;
       output_buffer *tmp_buffer = pp->buffer;
       pp->buffer = pp_warning_buffer;
       pp_really_flush (pp);
       warningcount += warningcount_buffered;
       werrorcount += werrorcount_buffered;
       gcc_assert (warningcount_buffered + werrorcount_buffered == 1);
+      pp->buffer = tmp_buffer;
       diagnostic_action_after_output (global_dc, 
 				      warningcount_buffered 
 				      ? DK_WARNING : DK_ERROR);
-      pp->buffer = tmp_buffer;
     }
 }
 
 
 /* Issue an error.  */
@@ -1379,12 +1378,12 @@ gfc_error_check (void)
       output_buffer *tmp_buffer = pp->buffer;
       pp->buffer = pp_error_buffer;
       pp_really_flush (pp);
       ++errorcount;
       gcc_assert (gfc_output_buffer_empty_p (pp_error_buffer));
-      diagnostic_action_after_output (global_dc, DK_ERROR);
       pp->buffer = tmp_buffer;
+      diagnostic_action_after_output (global_dc, DK_ERROR);
       return true;
     }
 
   return false;
 }
@@ -1470,10 +1469,12 @@ gfc_diagnostics_init (void)
   diagnostic_format_decoder (global_dc) = gfc_format_decoder;
   global_dc->caret_chars[0] = '1';
   global_dc->caret_chars[1] = '2';
   pp_warning_buffer = new (XNEW (output_buffer)) output_buffer ();
   pp_warning_buffer->flush_p = false;
+  /* pp_error_buffer is statically allocated.  This simplifies memory
+     management when using gfc_push/pop_error. */
   pp_error_buffer = &(error_buffer.buffer);
   pp_error_buffer->flush_p = false;
 }
 
 void