commit b1980f6d03f79ab57da8f32aa8cd9677dbe1d58f
Author: Peter Eisentraut <peter_e@gmx.net>
Date:   Thu Jan 31 22:08:53 2013 -0500

    PL/Tcl: Fix compiler warnings with Tcl 8.6
    
    Some constification was added in the Tcl APIs, so add the modifiers in
    PL/Tcl as well.

--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -18,6 +18,11 @@
 #define CONST84
 #endif
 
+/* ... and for Tcl 8.6. */
+#ifndef CONST86
+#define CONST86
+#endif
+
 #include "access/xact.h"
 #include "catalog/pg_proc.h"
 #include "catalog/pg_type.h"
@@ -258,7 +263,7 @@ pltcl_FinalizeNotifier(ClientData client
 }
 
 static void
-pltcl_SetTimer(Tcl_Time *timePtr)
+pltcl_SetTimer(CONST86 Tcl_Time *timePtr)
 {
 }
 
@@ -284,7 +289,7 @@ pltcl_ServiceModeHook(int mode)
 }
 
 static int
-pltcl_WaitForEvent(Tcl_Time *timePtr)
+pltcl_WaitForEvent(CONST86 Tcl_Time *timePtr)
 {
 	return 0;
 }
