* doc/global.n:

	* doc/upvar.n:
	* generic/tclVar.c (ObjMakeUpvar):
	* tests/upvar.test (upvar-8.11):
	* tests/var.test (var-3.11): Avoid creation of unusable variables:
	[Bug 600812] [TIP 184].

6 files changed, 54 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index 7be5697..1d7dd94 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2004-04-28  Miguel Sofer <msofer@users.sf.net>
+
+	* doc/global.n:
+	* doc/upvar.n:
+	* generic/tclVar.c (ObjMakeUpvar):
+	* tests/upvar.test (upvar-8.11):
+	* tests/var.test (var-3.11): Avoid creation of unusable variables:
+	[Bug 600812] [TIP 184].
+
 2004-04-28  Donal K. Fellows  <donal.k.fellows@man.ac.uk>
 
 	* doc/lsearch.n: Fixed fault in documentation of -index option [943448]
diff --git a/doc/global.n b/doc/global.n
index d4fd4c0..f8e502e 100644
--- a/doc/global.n
+++ b/doc/global.n
@@ -5,7 +5,7 @@
 '\" See the file "license.terms" for information on usage and redistribution
 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 '\" 
-'\" RCS: @(#) $Id: global.n,v 1.4 2002/06/11 13:22:35 msofer Exp $
+'\" RCS: @(#) $Id: global.n,v 1.5 2004/04/28 13:11:33 msofer Exp $
 '\" 
 .so man.macros
 .TH global n "" Tcl "Tcl Built-In Commands"
@@ -28,6 +28,10 @@ For the duration of the current procedure
 any reference to any of the \fIvarname\fRs
 will refer to the global variable by the same name.
 .PP
+\fIvarname\fR is always treated as the name of a variable, not an
+array element.  An error is returned if the name looks like an array element,
+such as \fBa(b)\fR.
+
 
 .SH "SEE ALSO"
 namespace(n), upvar(n), variable(n)
diff --git a/doc/upvar.n b/doc/upvar.n
index 2b2175e..84399c7 100644
--- a/doc/upvar.n
+++ b/doc/upvar.n
@@ -5,7 +5,7 @@
 '\" See the file "license.terms" for information on usage and redistribution
 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 '\" 
-'\" RCS: @(#) $Id: upvar.n,v 1.5 2000/11/21 15:56:21 dkf Exp $
+'\" RCS: @(#) $Id: upvar.n,v 1.6 2004/04/28 13:11:33 msofer Exp $
 '\" 
 .so man.macros
 .TH upvar n "" Tcl "Tcl Built-In Commands"
@@ -35,8 +35,8 @@ call;  it will be created the first time \fImyVar\fR is referenced, just like
 an ordinary variable.  There must not exist a variable by the
 name \fImyVar\fR at the time \fBupvar\fR is invoked.
 \fIMyVar\fR is always treated as the name of a variable, not an
-array element.  Even if the name looks like an array element,
-such as \fBa(b)\fR, a regular variable is created.
+array element.  An error is returned if the name looks like an array element,
+such as \fBa(b)\fR.
 \fIOtherVar\fR may refer to a scalar variable, an array,
 or an array element.
 \fBUpvar\fR returns an empty string.
diff --git a/generic/tclVar.c b/generic/tclVar.c
index 1b3068b..b3dbbee 100644
--- a/generic/tclVar.c
+++ b/generic/tclVar.c
@@ -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: tclVar.c,v 1.78 2004/04/06 22:25:56 dgp Exp $
+ * RCS: @(#) $Id: tclVar.c,v 1.79 2004/04/28 13:11:33 msofer Exp $
  */
 
 #include "tclInt.h"
@@ -3321,6 +3321,7 @@ ObjMakeUpvar(interp, framePtr, otherP1Ptr, otherP2, otherFlags, myName, myFlags,
     Var *otherPtr, *varPtr, *arrayPtr;
     CallFrame *varFramePtr;
     CONST char *errMsg;
+    CONST char *p;
 
     /*
      * Find "other" in "framePtr". If not looking up other in just the
@@ -3367,6 +3368,29 @@ ObjMakeUpvar(interp, framePtr, otherP1Ptr, otherP2, otherFlags, myName, myFlags,
 	}
 	
 	/*
+	 * Do not permit the new variable to look like an array reference,
+	 * as it will not be reachable in that case [Bug 600812, TIP 184].
+	 * The "definition" of what "looks like an array reference" is 
+	 * consistent (and must remain consistent) with the code in 
+	 * TclObjLookupVar().
+	 */
+
+	p = strstr(myName, "(");
+	if (p != NULL) {
+	    p += strlen(p)-1;
+	    if (*p == ')') {
+	        /*
+		 * myName looks like an array reference.
+		 */
+		    
+		Tcl_AppendResult((Tcl_Interp *) iPtr, "bad variable name \"",
+		        myName, "\": upvar won't create a scalar variable that ",
+		    "looks like an array element", (char *) NULL);
+		return TCL_ERROR;
+	    }
+	}
+
+	/*
 	 * Lookup and eventually create the new variable. Set the flag bit
 	 * LOOKUP_FOR_UPVAR to indicate the special resolution rules for 
 	 * upvar purposes: 
diff --git a/tests/upvar.test b/tests/upvar.test
index dcc2e23..ed9ce1d 100644
--- a/tests/upvar.test
+++ b/tests/upvar.test
@@ -11,7 +11,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: upvar.test,v 1.8 2003/11/14 20:44:47 dgp Exp $
+# RCS: @(#) $Id: upvar.test,v 1.9 2004/04/28 13:11:35 msofer Exp $
 
 if {[lsearch [namespace children] ::tcltest] == -1} {
     package require tcltest
@@ -336,6 +336,11 @@ test upvar-8.10 {upvar will create element alias for new array element} {
     array set upvarArray {}
     catch {upvar 0 upvarArray(elem) upvarArrayElemAlias}
 } {0}
+test upvar-8.11 {upvar will not create a variable that looks like an array} -body {
+    catch {unset upvarArray}
+    array set upvarArray {}
+    upvar 0 upvarArray(elem) upvarArrayElemAlias(elem)
+} -returnCodes 1 -match glob -result *
 
 if {[info commands testupvar] != {}} {
     test upvar-9.1 {Tcl_UpVar2 procedure} {
diff --git a/tests/var.test b/tests/var.test
index 8969384..c675d63 100644
--- a/tests/var.test
+++ b/tests/var.test
@@ -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: var.test,v 1.22 2003/05/12 17:20:41 msofer Exp $
+# RCS: @(#) $Id: var.test,v 1.23 2004/04/28 13:11:35 msofer Exp $
 #
 
 if {[lsearch [namespace children] ::tcltest] == -1} {
@@ -272,6 +272,11 @@ test var-3.10 {MakeUpvar, } {
 	set msg
     }
 } {1 1}
+test var-3.11 {MakeUpvar, my var looks like array elem} -body {
+    catch {unset aaaaa}
+    set aaaaa 789789
+    upvar #0 aaaaa foo(bar)
+} -returnCodes 1 -result {bad variable name "foo(bar)": upvar won't create a scalar variable that looks like an array element}
 
 if {[info commands testgetvarfullname] != {}} {
     test var-4.1 {Tcl_GetVariableName, global variable} {