[db36fa5122] Upgrade the index value parsing and encoding machinery.

Refactor many systems to make consistent use of it. Repairs many indexing
errors in corner cases.

1 files changed, 12 insertions, 11 deletions

diff --git a/generic/tclAssembly.c b/generic/tclAssembly.c
index 120fd9a..b6bebb6 100644
--- a/generic/tclAssembly.c
+++ b/generic/tclAssembly.c
@@ -2248,23 +2248,24 @@ GetListIndexOperand(
     Tcl_Token* tokenPtr = *tokenPtrPtr;
 				/* INOUT: Pointer to the next token in the
 				 * source code */
-    Tcl_Obj* intObj;		/* Integer from the source code */
-    int status;			/* Tcl status return */
-
-    /*
-     * Extract the next token as a string.
-     */
+    Tcl_Obj *value;
+    int status;
 
-    if (GetNextOperand(assemEnvPtr, tokenPtrPtr, &intObj) != TCL_OK) {
+    /* General operand validity check */
+    if (GetNextOperand(assemEnvPtr, tokenPtrPtr, &value) != TCL_OK) {
 	return TCL_ERROR;
     }
-
+     
+    /* Convert to an integer, advance to the next token and return. */
     /*
-     * Convert to an integer, advance to the next token and return.
+     * NOTE: Indexing a list with an index before it yields the
+     * same result as indexing after it, and might be more easily portable
+     * when list size limits grow.
      */
+    status = TclIndexEncode(interp, value,
+	    TCL_INDEX_BEFORE,TCL_INDEX_BEFORE, result);
 
-    status = TclGetIntForIndex(interp, intObj, -2, result);
-    Tcl_DecrRefCount(intObj);
+    Tcl_DecrRefCount(value);
     *tokenPtrPtr = TokenAfter(tokenPtr);
     return status;
 }