Don't allow upvar to a higher level

i.e. upvar of a global var to a proc var

Signed-off-by: Steve Bennett <steveb@workware.net.au>

3 files changed, 26 insertions, 0 deletions

diff --git a/jim.c b/jim.c
index ebc3dae..a204328 100644
--- a/jim.c
+++ b/jim.c
@@ -4066,6 +4066,14 @@ int Jim_SetVariableLink(Jim_Interp *interp, Jim_Obj *nameObjPtr,
     }
     Jim_IncrRefCount(targetNameObjPtr);
 
+    if (framePtr->level < targetCallFrame->level) {
+        Jim_SetResultFormatted(interp,
+            "bad variable name \"%#s\": upvar won't create namespace variable that refers to procedure variable",
+            nameObjPtr);
+        Jim_DecrRefCount(interp, targetNameObjPtr);
+        return JIM_ERR;
+    }
+
     /* Check for cycles. */
     if (framePtr == targetCallFrame) {
         Jim_Obj *objPtr = targetNameObjPtr;
diff --git a/regtest.tcl b/regtest.tcl
index 999d4b0..0f2e5b6 100644
--- a/regtest.tcl
+++ b/regtest.tcl
@@ -165,6 +165,19 @@ set t 6
 catch a
 puts "TEST 24 PASSED"
 
+# REGTEST 25
+# 14 Nov 2011 - link global var to proc var
+proc a {} {
+    set x 3
+    upvar 0 x ::globx
+}
+set globx 0
+catch {
+    a
+}
+incr globx
+puts "TEST 25 PASSED"
+
 # TAKE THE FOLLOWING puts AS LAST LINE
 
 puts "--- ALL TESTS PASSED ---"
diff --git a/tests/upvar.test b/tests/upvar.test
index 4b919a2..8d95c1d 100644
--- a/tests/upvar.test
+++ b/tests/upvar.test
@@ -340,6 +340,11 @@ test upvar-9.6 {upvar via global namespace} {
     list [catch p1 msg] $msg
 } {1 {can't upvar from variable to itself}}
 
+test upvar-9.7 {upvar to higher level} {
+    proc p1 {} { upvar 0 x ::globx }
+    list [catch p1 msg] $msg
+} {1 {bad variable name "::globx": upvar won't create namespace variable that refers to procedure variable}}
+
 catch {unset a}
 
 testreport