Index: doc/uplevel.n
==================================================================
--- doc/uplevel.n
+++ doc/uplevel.n
@@ -22,13 +22,13 @@
 the result of that evaluation.
 .PP
 If \fIlevel\fR is an integer then
 it gives a distance (up the procedure calling stack) to move before
 executing the command.  If \fIlevel\fR consists of \fB#\fR followed by
-a number then the number gives an absolute level number.  If \fIlevel\fR
+a integer then the level gives an absolute level.  If \fIlevel\fR
 is omitted then it defaults to \fB1\fR.  \fILevel\fR cannot be
-defaulted if the first \fIcommand\fR argument starts with a digit or \fB#\fR.
+defaulted if the first \fIcommand\fR argument is an integer or starts with \fB#\fR.
 .PP
 For example, suppose that procedure \fBa\fR was invoked
 from top-level, and that it called \fBb\fR, and that \fBb\fR called \fBc\fR.
 Suppose that \fBc\fR invokes the \fBuplevel\fR command.  If \fIlevel\fR
 is \fB1\fR or \fB#2\fR  or omitted, then the command will be executed

Index: generic/tclProc.c
==================================================================
--- generic/tclProc.c
+++ generic/tclProc.c
@@ -686,55 +686,19 @@
     Tcl_Interp *interp,		/* Interpreter in which to find frame. */
     const char *name,		/* String describing frame. */
     CallFrame **framePtrPtr)	/* Store pointer to frame here (or NULL if
 				 * global frame indicated). */
 {
-    register Interp *iPtr = (Interp *) interp;
-    int curLevel, level, result;
-    CallFrame *framePtr;
-
-    /*
-     * Parse string to figure out which level number to go to.
-     */
-
-    result = 1;
-    curLevel = iPtr->varFramePtr->level;
-    if (*name== '#') {
-	if (Tcl_GetInt(interp, name+1, &level) != TCL_OK || level < 0) {
-	    goto levelError;
-	}
-    } else if (isdigit(UCHAR(*name))) { /* INTL: digit */
-	if (Tcl_GetInt(interp, name, &level) != TCL_OK) {
-	    goto levelError;
-	}
-	level = curLevel - level;
-    } else {
-	level = curLevel - 1;
-	result = 0;
-    }
-
-    /*
-     * Figure out which frame to use, and return it to the caller.
-     */
-
-    for (framePtr = iPtr->varFramePtr; framePtr != NULL;
-	    framePtr = framePtr->callerVarPtr) {
-	if (framePtr->level == level) {
-	    break;
-	}
-    }
-    if (framePtr == NULL) {
-	goto levelError;
-    }
-
-    *framePtrPtr = framePtr;
-    return result;
-
-  levelError:
-    Tcl_SetObjResult(interp, Tcl_ObjPrintf("bad level \"%s\"", name));
-    Tcl_SetErrorCode(interp, "TCL", "VALUE", "STACKLEVEL", NULL);
-    return -1;
+	int result;
+	Tcl_Obj obj;
+
+	obj.bytes = (char *) name;
+	obj.length = strlen(name);
+	obj.typePtr = NULL;
+	result = TclObjGetFrame(interp, &obj, framePtrPtr);
+	TclFreeIntRep(&obj);
+	return result;
 }
 
 /*
  *----------------------------------------------------------------------
  *
@@ -768,10 +732,11 @@
 				 * global frame indicated). */
 {
     register Interp *iPtr = (Interp *) interp;
     int curLevel, level, result;
     const char *name = NULL;
+    Tcl_WideInt w;
 
     /*
      * Parse object to figure out which level number to go to.
      */
 
@@ -783,29 +748,37 @@
      * a generation of a stringrep.
      */
 
     if (objPtr == NULL) {
 	/* Do nothing */
-    } else if (TCL_OK == Tcl_GetIntFromObj(NULL, objPtr, &level)
-	    && (level >= 0)) {
-	level = curLevel - level;
-	result = 1;
+    } else if (TCL_OK == Tcl_GetIntFromObj(NULL, objPtr, &level)) {
+	Tcl_GetWideIntFromObj(NULL, objPtr, &w);
+	if (w < 0 || w > INT_MAX || curLevel > w + INT_MAX) {
+	    result = -1;
+	} else {
+	    level = curLevel - level;
+	    result = 1;
+	}
     } else if (objPtr->typePtr == &levelReferenceType) {
 	level = (int) objPtr->internalRep.wideValue;
 	result = 1;
     } else {
 	name = TclGetString(objPtr);
 	if (name[0] == '#') {
-	    if (TCL_OK == Tcl_GetInt(NULL, name+1, &level) && level >= 0) {
-		TclFreeIntRep(objPtr);
-		objPtr->typePtr = &levelReferenceType;
-		objPtr->internalRep.wideValue = level;
-		result = 1;
+	    if (TCL_OK == Tcl_GetInt(NULL, name+1, &level)) {
+		if (level < 0 || (level > 0 && name[1] == '-')) {
+		    result = -1;
+		} else {
+		    TclFreeIntRep(objPtr);
+		    objPtr->typePtr = &levelReferenceType;
+		    objPtr->internalRep.wideValue = level;
+		    result = 1;
+		}
 	    } else {
 		result = -1;
 	    }
-	} else if (isdigit(UCHAR(name[0]))) { /* INTL: digit */
+	} else if (TclGetWideBitsFromObj(interp, objPtr, &w) == TCL_OK) {
 	    /*
 	     * If this were an integer, we'd have succeeded already.
 	     * Docs say we have to treat this as a 'bad level'  error.
 	     */
 	    result = -1;
@@ -812,11 +785,10 @@
 	}
     }
 
     if (result == 0) {
 	level = curLevel - 1;
-	name = "1";
     }
     if (result != -1) {
 	if (level >= 0) {
 	    CallFrame *framePtr;
 	    for (framePtr = iPtr->varFramePtr; framePtr != NULL;
@@ -825,15 +797,15 @@
 		    *framePtrPtr = framePtr;
 		    return result;
 		}
 	    }
 	}
-	if (name == NULL) {
-	    name = TclGetString(objPtr);
-	}
     }
 
+    if (name == NULL) {
+	name = TclGetString(objPtr);
+    }
     Tcl_SetObjResult(interp, Tcl_ObjPrintf("bad level \"%s\"", name));
     Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LEVEL", name, NULL);
     return -1;
 }
 

Index: tests/uplevel.test
==================================================================
--- tests/uplevel.test
+++ tests/uplevel.test
@@ -135,31 +135,31 @@
     apply {{} {uplevel [expr 1] {}}}
 } {}
 test uplevel-4.16 {level parsing} {
     apply {{} {uplevel #[expr 1] {}}}
 } {}
-test uplevel-4.17 {level parsing} {
+test uplevel-4.17 {level parsing} -returnCodes error -body {
     apply {{} {uplevel -0xffffffff {}}}
-} {}
-test uplevel-4.18 {level parsing} {
+} -result {bad level "-0xffffffff"}
+test uplevel-4.18 {level parsing} -returnCodes error -body {
     apply {{} {uplevel #-0xffffffff {}}}
-} {}
-test uplevel-4.19 {level parsing} {
+} -result {bad level "#-0xffffffff"}
+test uplevel-4.19 {level parsing} -returnCodes error -body {
     apply {{} {uplevel [expr -0xffffffff] {}}}
-} {}
-test uplevel-4.20 {level parsing} {
+} -result {bad level "-4294967295"}
+test uplevel-4.20 {level parsing} -returnCodes error -body {
     apply {{} {uplevel #[expr -0xffffffff] {}}}
-} {}
+} -result {bad level "#-4294967295"}
 test uplevel-4.21 {level parsing} -body {
     apply {{} {uplevel -1 {}}}
-} -returnCodes error -result {invalid command name "-1"}
+} -returnCodes error -result {bad level "-1"}
 test uplevel-4.22 {level parsing} -body {
     apply {{} {uplevel #-1 {}}}
 } -returnCodes error -result {bad level "#-1"}
 test uplevel-4.23 {level parsing} -body {
     apply {{} {uplevel [expr -1] {}}}
-} -returnCodes error -result {invalid command name "-1"}
+} -returnCodes error -result {bad level "-1"}
 test uplevel-4.24 {level parsing} -body {
     apply {{} {uplevel #[expr -1] {}}}
 } -returnCodes error -result {bad level "#-1"}
 test uplevel-4.25 {level parsing} -body {
     apply {{} {uplevel 0xffffffff {}}}
@@ -173,17 +173,17 @@
 test uplevel-4.28 {level parsing} -body {
     apply {{} {uplevel #[expr 0xffffffff] {}}}
 } -returnCodes error -result {bad level "#4294967295"}
 test uplevel-4.29 {level parsing} -body {
     apply {{} {uplevel 0.2 {}}}
-} -returnCodes error -result {bad level "0.2"}
+} -returnCodes error -result {invalid command name "0.2"}
 test uplevel-4.30 {level parsing} -body {
     apply {{} {uplevel #0.2 {}}}
 } -returnCodes error -result {bad level "#0.2"}
 test uplevel-4.31 {level parsing} -body {
     apply {{} {uplevel [expr 0.2] {}}}
-} -returnCodes error -result {bad level "0.2"}
+} -returnCodes error -result {invalid command name "0.2"}
 test uplevel-4.32 {level parsing} -body {
     apply {{} {uplevel #[expr 0.2] {}}}
 } -returnCodes error -result {bad level "#0.2"}
 test uplevel-4.33 {level parsing} -body {
     apply {{} {uplevel .2 {}}}
@@ -191,11 +191,11 @@
 test uplevel-4.34 {level parsing} -body {
     apply {{} {uplevel #.2 {}}}
 } -returnCodes error -result {bad level "#.2"}
 test uplevel-4.35 {level parsing} -body {
     apply {{} {uplevel [expr .2] {}}}
-} -returnCodes error -result {bad level "0.2"}
+} -returnCodes error -result {invalid command name "0.2"}
 test uplevel-4.36 {level parsing} -body {
     apply {{} {uplevel #[expr .2] {}}}
 } -returnCodes error -result {bad level "#0.2"}