Change sourceRoot resolution to match the spec

dist/source-map.js

@@ -1154,6 +1154,59 @@ return /******/ (function(modules) { // webpackBootstrap
 	}
 	exports.parseSourceMapInput = parseSourceMapInput;
 
+	/**
+	 * Compute the URL of a source given the the source root, the source's
+	 * URL, and the source map's URL.
+	 */
+	function computeSourceURL(sourceRoot, sourceURL, sourceMapURL) {
+	  sourceURL = sourceURL || '';
+
+	  if (sourceRoot) {
+	    // This follows what Chrome does.
+	    if (sourceRoot[sourceRoot.length - 1] !== '/' && sourceURL[0] !== '/') {
+	      sourceRoot += '/';
+	    }
+	    // The spec says:
+	    //   Line 4: An optional source root, useful for relocating source
+	    //   files on a server or removing repeated values in the
+	    //   “sources” entry.  This value is prepended to the individual
+	    //   entries in the “source” field.
+	    sourceURL = sourceRoot + sourceURL;
+	  }
+
+	  // Historically, SourceMapConsumer did not take the sourceMapURL as
+	  // a parameter.  This mode is still somewhat supported, which is why
+	  // this code block is conditional.  However, it's preferable to pass
+	  // the source map URL to SourceMapConsumer, so that this function
+	  // can implement the source URL resolution algorithm as outlined in
+	  // the spec.  This block is basically the equivalent of:
+	  //    new URL(sourceURL, sourceMapURL).toString()
+	  // ... except it avoids using URL, which wasn't available in the
+	  // older releases of node still supported by this library.
+	  //
+	  // The spec says:
+	  //   If the sources are not absolute URLs after prepending of the
+	  //   “sourceRoot”, the sources are resolved relative to the
+	  //   SourceMap (like resolving script src in a html document).
+	  if (sourceMapURL) {
+	    var parsed = urlParse(sourceMapURL);
+	    if (!parsed) {
+	      throw new Error("sourceMapURL could not be parsed");
+	    }
+	    if (parsed.path) {
+	      // Strip the last path component, but keep the "/".
+	      var index = parsed.path.lastIndexOf('/');
+	      if (index >= 0) {
+	        parsed.path = parsed.path.substring(0, index + 1);
+	      }
+	    }
+	    sourceURL = join(urlGenerate(parsed), sourceURL);
+	  }
+
+	  return normalize(sourceURL);
+	}
+	exports.computeSourceURL = computeSourceURL;
+
 
 /***/ }),
 /* 5 */
@@ -1384,15 +1437,15 @@ return /******/ (function(modules) { // webpackBootstrap
 	var base64VLQ = __webpack_require__(2);
 	var quickSort = __webpack_require__(9).quickSort;
 
-	function SourceMapConsumer(aSourceMap) {
+	function SourceMapConsumer(aSourceMap, aSourceMapURL) {
 	  var sourceMap = aSourceMap;
 	  if (typeof aSourceMap === 'string') {
 	    sourceMap = util.parseSourceMapInput(aSourceMap);
 	  }
 
 	  return sourceMap.sections != null
-	    ? new IndexedSourceMapConsumer(sourceMap)
-	    : new BasicSourceMapConsumer(sourceMap);
+	    ? new IndexedSourceMapConsumer(sourceMap, aSourceMapURL)
+	    : new BasicSourceMapConsumer(sourceMap, aSourceMapURL);
 	}
 
 	SourceMapConsumer.fromSourceMap = function(aSourceMap) {
@@ -1518,9 +1571,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	    var sourceRoot = this.sourceRoot;
 	    mappings.map(function (mapping) {
 	      var source = mapping.source === null ? null : this._sources.at(mapping.source);
-	      if (source != null && sourceRoot != null) {
-	        source = util.join(sourceRoot, source);
-	      }
+	      source = util.computeSourceURL(sourceRoot, source, this._sourceMapURL);
 	      return {
 	        source: source,
 	        generatedLine: mapping.generatedLine,
@@ -1634,7 +1685,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	 * query for information about the original file positions by giving it a file
 	 * position in the generated source.
 	 *
-	 * The only parameter is the raw source map (either as a JSON string, or
+	 * The first parameter is the raw source map (either as a JSON string, or
 	 * already parsed to an object). According to the spec, source maps have the
 	 * following attributes:
 	 *
@@ -1657,9 +1708,13 @@ return /******/ (function(modules) { // webpackBootstrap
 	 *       mappings: "AA,AB;;ABCDE;"
 	 *     }
 	 *
+	 * The second parameter, if given, is a string whose value is the URL
+	 * at which the source map was found.  This URL is used to compute the
+	 * sources array.
+	 *
 	 * [0]: https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit?pli=1#
 	 */
-	function BasicSourceMapConsumer(aSourceMap) {
+	function BasicSourceMapConsumer(aSourceMap, aSourceMapURL) {
 	  var sourceMap = aSourceMap;
 	  if (typeof aSourceMap === 'string') {
 	    sourceMap = util.parseSourceMapInput(aSourceMap);
@@ -1711,6 +1766,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	  this.sourceRoot = sourceRoot;
 	  this.sourcesContent = sourcesContent;
 	  this._mappings = mappings;
+	  this._sourceMapURL = aSourceMapURL;
 	  this.file = file;
 	}
 
@@ -1722,10 +1778,12 @@ return /******/ (function(modules) { // webpackBootstrap
 	 *
 	 * @param SourceMapGenerator aSourceMap
 	 *        The source map that will be consumed.
+	 * @param String aSourceMapURL
+	 *        The URL at which the source map can be found (optional)
 	 * @returns BasicSourceMapConsumer
 	 */
 	BasicSourceMapConsumer.fromSourceMap =
-	  function SourceMapConsumer_fromSourceMap(aSourceMap) {
+	  function SourceMapConsumer_fromSourceMap(aSourceMap, aSourceMapURL) {
 	    var smc = Object.create(BasicSourceMapConsumer.prototype);
 
 	    var names = smc._names = ArraySet.fromArray(aSourceMap._names.toArray(), true);
@@ -1734,6 +1792,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	    smc.sourcesContent = aSourceMap._generateSourcesContent(smc._sources.toArray(),
 	                                                            smc.sourceRoot);
 	    smc.file = aSourceMap._file;
+	    smc._sourceMapURL = aSourceMapURL;
 
 	    // Because we are modifying the entries (by converting string sources and
 	    // names to indices into the sources and names ArraySets), we have to make
@@ -1781,7 +1840,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	Object.defineProperty(BasicSourceMapConsumer.prototype, 'sources', {
 	  get: function () {
 	    return this._sources.toArray().map(function (s) {
-	      return this.sourceRoot != null ? util.join(this.sourceRoot, s) : s;
+	      return util.computeSourceURL(this.sourceRoot, s, this._sourceMapURL);
 	    }, this);
 	  }
 	});
@@ -2005,9 +2064,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	        var source = util.getArg(mapping, 'source', null);
 	        if (source !== null) {
 	          source = this._sources.at(source);
-	          if (this.sourceRoot != null) {
-	            source = util.join(this.sourceRoot, source);
-	          }
+	          source = util.computeSourceURL(this.sourceRoot, source, this._sourceMapURL);
 	        }
 	        var name = util.getArg(mapping, 'name', null);
 	        if (name !== null) {
@@ -2054,12 +2111,23 @@ return /******/ (function(modules) { // webpackBootstrap
 	      return null;
 	    }
 
+	    var relativeSource = aSource;
 	    if (this.sourceRoot != null) {
-	      aSource = util.relative(this.sourceRoot, aSource);
+	      relativeSource = util.relative(this.sourceRoot, relativeSource);
+	    }
+
+	    if (this._sources.has(relativeSource)) {
+	      return this.sourcesContent[this._sources.indexOf(relativeSource)];
 	    }
 
-	    if (this._sources.has(aSource)) {
-	      return this.sourcesContent[this._sources.indexOf(aSource)];
+	    // Maybe aSource is an absolute URL as returned by |sources|.  In
+	    // this case we can't simply undo the transform.
+	    var sourceArray = this.sources;
+	    var i;
+	    for (i = 0; i < sourceArray.length; ++i) {
+	      if (sourceArray[i] == aSource) {
+	        return this.sourcesContent[i];
+	      }
 	    }
 
 	    var url;
@@ -2069,15 +2137,15 @@ return /******/ (function(modules) { // webpackBootstrap
 	      // many users. We can help them out when they expect file:// URIs to
 	      // behave like it would if they were running a local HTTP server. See
 	      // https://bugzilla.mozilla.org/show_bug.cgi?id=885597.
-	      var fileUriAbsPath = aSource.replace(/^file:\/\//, "");
+	      var fileUriAbsPath = relativeSource.replace(/^file:\/\//, "");
 	      if (url.scheme == "file"
 	          && this._sources.has(fileUriAbsPath)) {
 	        return this.sourcesContent[this._sources.indexOf(fileUriAbsPath)]
 	      }
 
 	      if ((!url.path || url.path == "/")
-	          && this._sources.has("/" + aSource)) {
-	        return this.sourcesContent[this._sources.indexOf("/" + aSource)];
+	          && this._sources.has("/" + relativeSource)) {
+	        return this.sourcesContent[this._sources.indexOf("/" + relativeSource)];
 	      }
 	    }
 
@@ -2089,7 +2157,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	      return null;
 	    }
 	    else {
-	      throw new Error('"' + aSource + '" is not in the SourceMap.');
+	      throw new Error('"' + relativeSource + '" is not in the SourceMap.');
 	    }
 	  };
 
@@ -2173,7 +2241,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	 * that it takes "indexed" source maps (i.e. ones with a "sections" field) as
 	 * input.
 	 *
-	 * The only parameter is a raw source map (either as a JSON string, or already
+	 * The first parameter is a raw source map (either as a JSON string, or already
 	 * parsed to an object). According to the spec for indexed source maps, they
 	 * have the following attributes:
 	 *
@@ -2210,9 +2278,13 @@ return /******/ (function(modules) { // webpackBootstrap
 	 *    }],
 	 *  }
 	 *
+	 * The second parameter, if given, is a string whose value is the URL
+	 * at which the source map was found.  This URL is used to compute the
+	 * sources array.
+	 *
 	 * [0]: https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit#heading=h.535es3xeprgt
 	 */
-	function IndexedSourceMapConsumer(aSourceMap) {
+	function IndexedSourceMapConsumer(aSourceMap, aSourceMapURL) {
 	  var sourceMap = aSourceMap;
 	  if (typeof aSourceMap === 'string') {
 	    sourceMap = util.parseSourceMapInput(aSourceMap);
@@ -2255,7 +2327,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	        generatedLine: offsetLine + 1,
 	        generatedColumn: offsetColumn + 1
 	      },
-	      consumer: new SourceMapConsumer(util.getArg(s, 'map'))
+	      consumer: new SourceMapConsumer(util.getArg(s, 'map'), aSourceMapURL)
 	    }
 	  });
 	}
@@ -2441,9 +2513,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	        var mapping = sectionMappings[j];
 
 	        var source = section.consumer._sources.at(mapping.source);
-	        if (section.consumer.sourceRoot !== null) {
-	          source = util.join(section.consumer.sourceRoot, source);
-	        }
+	        source = util.computeSourceURL(section.consumer.sourceRoot, source, this._sourceMapURL);
 	        this._sources.add(source);
 	        source = this._sources.indexOf(source);