Bug [8dd2807066] - crash on expr(max(abs())

Author: apnadkarni

generic/tclExecute.c

@@ -8765,6 +8765,13 @@ TclCompareTwoNumbers(
     double d1, d2, tmp;
     Tcl_WideInt w1, w2;
 
+    if (valuePtr == value2Ptr) {
+	/* 
+	 * Bug https://core.tcl-lang.org/tcl/tktview/8dd28070. Protect
+	 * multiple mp_clear's of the same bignum.
+	 */
+	return MP_EQ;
+}
     (void) GetNumberFromObj(NULL, valuePtr, &ptr1, &type1);
     (void) GetNumberFromObj(NULL, value2Ptr, &ptr2, &type2);
 

tests/expr.test

@@ -7456,6 +7456,10 @@ test expr-62.10 {TIP 582: comments can go inside function calls} {
 	     (1,2)}
 } 2
 
+test expr-bug-8dd2807066 {Bug 8dd2807066} {
+    expr {max(abs(-668336881543038127783364011867))}
+} 668336881543038127783364011867
+
 # Bug e3dcab1d14 TODO: Need to work out a test case that fails
 # without tcl_precision, which has been eliminated in 9.0