setBreakpoint w/o arguments should set one on a current line

Author: indutny

lib/_debugger.js

@@ -1110,6 +1110,12 @@ Interface.prototype.setBreakpoint = function(script, line,
       scriptId,
       ambiguous;
 
+  // setBreakpoint() should insert breakpoint on current line
+  if (script === undefined) {
+    script = this.client.currentScript;
+    line = this.client.currentSourceLine + 1;
+  }
+
   if (script != +script && !this.client.scripts[script]) {
     Object.keys(this.client.scripts).forEach(function(id) {
       if (self.client.scripts[id].name.indexOf(script) !== -1) {