DevTools: Show -0 for negative zero in console.

Source/core/inspector/InjectedScriptSource.js

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 69 matching lines @@
     {
         return func.apply(thisObject, args.concat(slice(arguments)));
     }
     bound.toString = function() {
         return "bound: " + func;
     };
     return bound;
 }
 
 /**
+ * @param {number} x
+ * @return {boolean}
+ */
+function isNegativeZero(x)
+{
+    return x === 0 && 1 / x < 0;
+}
+
+/**
  * @constructor
  */
 var InjectedScript = function()
 {
     /** @type {number} */
     this._lastBoundObjectId = 1;
     /** @type {!Object.<number, Object>} */
     this._idToWrappedObject = {};
     /** @type {!Object.<number, string>} */
     this._idToObjectGroupName = {};
@@ skipping 823 matching lines @@
     if (injectedScript.isPrimitiveValue(object) || object === null || forceValueType) {
         // We don't send undefined values over JSON.
         if (this.type !== "undefined")
             this.value = object;
 
         // Null object is object with 'null' subtype.
         if (object === null)
             this.subtype = "null";
 
         // Provide user-friendly number values.
-        if (this.type === "number")
-            this.description = toString(object);
+        if (this.type === "number") {
+            if (isNegativeZero(/** @type {number} */ (object)))
+                this.description = "-0";
+            else
+                this.description = toString(object);
+        }
         return;
     }
 
     object = /** @type {Object} */ (object);
 
     this.objectId = injectedScript._bind(object, objectGroupName);
     var subtype = injectedScript._subtype(object);
     if (subtype)
         this.subtype = subtype;
     this.className = InjectedScriptHost.internalConstructorName(object);
@@ skipping 77 matching lines @@
                 const maxLength = 100;
                 var type = typeof value;
                 if (!descriptor.enumerable && type === "function")
                     continue;
 
                 if (InjectedScript.primitiveTypes[type]) {
                     if (type === "string" && value.length > maxLength) {
                         value = this._abbreviateString(value, maxLength, true);
                         preview.lossless = false;
                     }
-                    this._appendPropertyPreview(preview, { name: name, type: type, value: toString(value) }, propertiesThreshold);
+                    var description = (type === "number" && isNegativeZero(value)) ? "-0" : toString(value);

[yurys, 2013/11/22 18:00:09]

The code for the number serialization repeats twice already, let's extract it
into a function:

return (isNegativeZero(/** @type {number} */ (object))) ? "-0" :
toString(object);

+                    this._appendPropertyPreview(preview, { name: name, type: type, value: description }, propertiesThreshold);
                     continue;
                 }
 
                 if (secondLevelKeys === null || secondLevelKeys) {
                     var subPreview = this._generatePreview(value, secondLevelKeys || undefined, undefined, false, isTable);
                     var property = { name: name, type: type, valuePreview: subPreview };
                     this._appendPropertyPreview(preview, property, propertiesThreshold);
                     if (!subPreview.lossless)
                         preview.lossless = false;
                     if (subPreview.overflow)
@@ skipping 427 matching lines @@
      */
     _logEvent: function(event)
     {
         inspectedWindow.console.log(event.type, event);
     }
 }
 
 injectedScript._commandLineAPIImpl = new CommandLineAPIImpl();
 return injectedScript;
 })