Make sure that Context.getSourcePositionFromStack never returns negative numbers and uses 0 to indicate absence of line information. It accounts for differences between JVMs when dealing with incomplete debug information.

git-svn-id: svn://10.0.0.236/trunk@156952 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/js/rhino/src/org/mozilla/javascript/Context.java

@@ -2346,6 +2346,9 @@ public class Context
                     String lineStr = s.substring(colon + 1, close);
                     try {
                         linep[0] = Integer.parseInt(lineStr);
+                        if (linep[0] < 0) {
+                            linep[0] = 0;
+                        }
                         return fileStr;
                     }
                     catch (NumberFormatException e) {