* generic/tclBasic.c: Fix for (among others) [Bug 2699087]

	* generic/tclCmdAH.c:   Tailcalls now perform properly even from
	* generic/tclExecute.c: within [eval]ed scripts.
	* generic/tclInt.h:     More tests missing, as well as proper
	exploration and testing of the interaction with "redirectors" like
	interp-alias (suspect that it does not happen in constant space)
	and pure-eval commands.

6 files changed, 99 insertions, 34 deletions

diff --git a/ChangeLog b/ChangeLog
index 72138dc..1cb2ce0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2009-03-21  Miguel Sofer  <msofer@users.sf.net>
 
+	* generic/tclBasic.c:   Fix for (among others) [Bug 2699087]
+	* generic/tclCmdAH.c:   Tailcalls now perform properly even from 
+	* generic/tclExecute.c: within [eval]ed scripts.
+	* generic/tclInt.h:     More tests missing, as well as proper
+	exploration and testing of the interaction with "redirectors" like 
+	interp-alias (suspect that it does not happen in constant space)
+	and pure-eval commands.
+
 	* generic/tclExecute.c: proper fix for [Bug 2415422]. Reenabled 
 	* tests/nre.test:       the failing assertion that was disabled on 
 	2008-12-18: the assertion is correct, the fault was in the
diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index 739732f..c40cd49 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -16,7 +16,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclBasic.c,v 1.388 2009/03/19 23:31:37 msofer Exp $
+ * RCS: @(#) $Id: tclBasic.c,v 1.389 2009/03/21 09:42:06 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -7988,8 +7988,9 @@ TclNRTailcallObjCmd(
 {
     Interp *iPtr = (Interp *) interp;
     TEOV_callback *tailcallPtr;
-    Tcl_Obj *listPtr;
-    Namespace *nsPtr = iPtr->varFramePtr->nsPtr;
+    Tcl_Obj *listPtr, *nsObjPtr;
+    Tcl_Namespace *nsPtr = (Tcl_Namespace *) iPtr->varFramePtr->nsPtr;
+    Tcl_Namespace *ns1Ptr;
     
     if (objc < 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "command ?arg ...?");
@@ -8004,10 +8005,16 @@ TclNRTailcallObjCmd(
 	return TCL_ERROR;
     }
 
-    nsPtr->activationCount++;
     listPtr = Tcl_NewListObj(objc-1, objv+1);
     Tcl_IncrRefCount(listPtr);
 
+    nsObjPtr = Tcl_NewStringObj(nsPtr->fullName, -1);
+    if ((TCL_OK != TclGetNamespaceFromObj(interp, nsObjPtr, &ns1Ptr))
+	    || (nsPtr != ns1Ptr)) {
+	Tcl_Panic("Tailcall failed to find the proper namespace");
+    }
+    Tcl_IncrRefCount(nsObjPtr);
+    
     /*
      * Add two callbacks: first the one to actually evaluate the tailcalled
      * command, then the one that signals TEBC to stash the first at its
@@ -8017,7 +8024,7 @@ TclNRTailcallObjCmd(
      * TclNRAddCallBack macro to build the callback)
      */
 
-    TclNRAddCallback(interp, NRTailcallEval, listPtr, nsPtr, NULL, NULL);
+    TclNRAddCallback(interp, NRTailcallEval, listPtr, nsObjPtr, NULL, NULL);
     tailcallPtr = TOP_CB(interp);
     TOP_CB(interp) = tailcallPtr->nextPtr;
 
@@ -8033,27 +8040,19 @@ NRTailcallEval(
 {
     Interp *iPtr = (Interp *) interp;
     Tcl_Obj *listPtr = data[0];
-    Namespace *nsPtr = data[1];
-    int omit = PTR2INT(data[2]);
+    Tcl_Obj *nsObjPtr = data[1];
+    Tcl_Namespace *nsPtr;
     int objc;
     Tcl_Obj **objv;
 
-    TclNRDeferCallback(interp, TailcallCleanup, listPtr, NULL, NULL, NULL);
-    if (!omit && (result == TCL_OK)) {
-	iPtr->lookupNsPtr = nsPtr;
-	ListObjGetElements(listPtr, objc, objv);
-	result = TclNREvalObjv(interp, objc, objv, 0, NULL);
-    }
-
-    nsPtr->activationCount--;
-    if ((nsPtr->flags & NS_DYING)
-	    && (nsPtr->activationCount - (nsPtr == iPtr->globalNsPtr) == 0)) {
-	/*
-	 * FIXME NRE tailcall: is this the proper way to manage this? This is
-	 * like what CallFrames do.
-	 */
-
-	Tcl_DeleteNamespace((Tcl_Namespace *) nsPtr);
+    TclNRDeferCallback(interp, TailcallCleanup, listPtr, nsObjPtr, NULL, NULL);
+    if (result == TCL_OK) {
+	result = TclGetNamespaceFromObj(interp, nsObjPtr, &nsPtr);
+	if (result == TCL_OK) {
+	    iPtr->lookupNsPtr = (Namespace *) nsPtr;
+	    ListObjGetElements(listPtr, objc, objv);
+	    result = TclNREvalObjv(interp, objc, objv, 0, NULL);
+	}
     }
     return result;
 }
@@ -8065,8 +8064,19 @@ TailcallCleanup(
     int result)
 {
     Tcl_DecrRefCount((Tcl_Obj *) data[0]);
+    Tcl_DecrRefCount((Tcl_Obj *) data[1]);
     return result;
 }
+
+void
+TclClearTailcall(
+    Tcl_Interp *interp,
+    TEOV_callback *tailcallPtr)
+{
+    TailcallCleanup(tailcallPtr->data, interp, TCL_OK);
+    TCLNR_FREE(interp, tailcallPtr);
+}
+
 
 void
 Tcl_NRAddCallback(
diff --git a/generic/tclCmdAH.c b/generic/tclCmdAH.c
index c8829f8..a00fff8 100644
--- a/generic/tclCmdAH.c
+++ b/generic/tclCmdAH.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclCmdAH.c,v 1.115 2009/02/03 23:34:33 nijtmans Exp $
+ * RCS: @(#) $Id: tclCmdAH.c,v 1.116 2009/03/21 09:42:06 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -302,12 +302,26 @@ CatchObjCmdCallback(
     Tcl_Interp *interp,
     int result)
 {
+    Interp *iPtr = (Interp *) interp;
     int objc = PTR2INT(data[0]);
     Tcl_Obj *varNamePtr = data[1];
     Tcl_Obj *optionVarNamePtr = data[2];
     int rewind = ((Interp *) interp)->execEnvPtr->rewind;
 
     /*
+     * catch has to disable any tailcall
+     */
+
+    if (iPtr->varFramePtr->tailcallPtr) {
+	TclClearTailcall(interp, iPtr->varFramePtr->tailcallPtr);
+	iPtr->varFramePtr->tailcallPtr = NULL;
+	result = TCL_ERROR;
+	Tcl_SetResult(interp,"Tailcall called from within a catch environment",
+		TCL_STATIC);
+    }	
+
+
+    /*
      * We disable catch in interpreters where the limit has been exceeded.
      */
 
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index 99bf84e..b00848a 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -14,7 +14,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclExecute.c,v 1.432 2009/03/21 06:55:31 msofer Exp $
+ * RCS: @(#) $Id: tclExecute.c,v 1.433 2009/03/21 09:42:07 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -1871,18 +1871,15 @@ TclExecuteByteCode(
 		    fprintf(stdout, "   Tailcall request received\n");
 		}
 #endif
-		TEOV_callback *tailcallPtr = param;
-
-		iPtr->varFramePtr->tailcallPtr = tailcallPtr;
-		
 		if (catchTop != initCatchTop) {
-		    tailcallPtr->data[2] = INT2PTR(1);
+		    TclClearTailcall(interp, param);
 		    result = TCL_ERROR;
 		    Tcl_SetResult(interp,"Tailcall called from within a catch environment",
 			    TCL_STATIC);
 		    pc--;
 		    goto checkForCatch;
 		}
+		iPtr->varFramePtr->tailcallPtr = param;
 		goto abnormalReturn;
 	    }
 	    case TCL_NR_YIELD_TYPE: { /*[yield] */
@@ -1995,6 +1992,15 @@ TclExecuteByteCode(
 	 */
 
 	if (iPtr->varFramePtr->tailcallPtr) {
+	    if (catchTop != initCatchTop) {
+		TclClearTailcall(interp, iPtr->varFramePtr->tailcallPtr);
+		iPtr->varFramePtr->tailcallPtr = NULL;
+		result = TCL_ERROR;
+		Tcl_SetResult(interp,"Tailcall called from within a catch environment",
+			TCL_STATIC);
+		pc--;
+		goto checkForCatch;
+	    }
 	    goto abnormalReturn;
 	}
     
@@ -7759,6 +7765,19 @@ TclExecuteByteCode(
 
     abnormalReturn:
 	TCL_DTRACE_INST_LAST();
+
+	/*
+	 * Winding down: insure that all pending cleanups are done before
+	 * dropping out of this bytecode. 
+	 */
+	if (TOP_CB(interp) != bottomPtr->rootPtr) {
+	    result = TclNRRunCallbacks(interp, result, bottomPtr->rootPtr, 1);
+	
+	    if (TOP_CB(interp) != bottomPtr->rootPtr) {
+		Tcl_Panic("Abnormal return with busy callback stack");
+	    }
+	}
+	
 	/*
 	 * Clear all expansions and same-level NR calls.
 	 *
diff --git a/generic/tclInt.h b/generic/tclInt.h
index 48473bd..3c45cc1 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -15,7 +15,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclInt.h,v 1.419 2009/03/19 23:31:37 msofer Exp $
+ * RCS: @(#) $Id: tclInt.h,v 1.420 2009/03/21 09:42:07 msofer Exp $
  */
 
 #ifndef _TCLINT
@@ -2603,6 +2603,10 @@ MODULE_SCOPE Tcl_ObjCmdProc TclNRTailcallObjCmd;
 MODULE_SCOPE Tcl_ObjCmdProc TclNRCoroutineObjCmd;
 MODULE_SCOPE Tcl_ObjCmdProc TclNRYieldObjCmd;
 
+MODULE_SCOPE void TclClearTailcall(Tcl_Interp *interp,
+	            struct TEOV_callback *tailcallPtr);
+
+
 /*
  *----------------------------------------------------------------
  * Procedures shared among Tcl modules but not used by the outside world:
diff --git a/tests/tailcall.test b/tests/tailcall.test
index fb6d662..4cfbebf 100644
--- a/tests/tailcall.test
+++ b/tests/tailcall.test
@@ -9,7 +9,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: tailcall.test,v 1.3 2009/03/21 03:43:53 msofer Exp $
+# RCS: @(#) $Id: tailcall.test,v 1.4 2009/03/21 09:42:07 msofer Exp $
 
 if {[lsearch [namespace children] ::tcltest] == -1} {
     package require tcltest
@@ -221,7 +221,7 @@ test tailcall-9 {tailcall factorial} -setup {
     rename fact {}
 } -result {1 120 3628800 1307674368000}
 
-test tailcall-10a {tailcall and eval} -constraints {knownBug} -setup {
+test tailcall-10a {tailcall and eval} -setup {
     set ::x 0
     proc a {} {
 	eval [list tailcall lappend ::x 2]
@@ -432,7 +432,17 @@ test tailcall-12.2 {[Bug 2649975]} -setup {
 1: exiting from foo's alpha
 }
 
-test tailcall-12.3 {[Bug 2695587]} -setup {
+test tailcall-12.3a {[Bug 2695587]} -setup {
+    proc a {} {
+	list [catch [list tailcall foo] msg] $msg
+    }
+} -body {
+    a
+} -cleanup {
+    rename a {}
+} -result {1 {Tailcall called from within a catch environment}}
+
+test tailcall-12.3b {[Bug 2695587]} -setup {
     proc a {} {
 	list [catch {tailcall foo} msg] $msg
     }