Set relativeLinkPrefix before setting titlePageURI

* Fixes the inconsistency reported in T155070 where internal cite
  links were missing the "./" prefix.

* Since parser tests cannot easily verify this expectation (which is
  how we couldn't catch this in the first place), added a mocha test
  as a regression spec to ensure that internal cite links continue
  to use "./" prefixed urls.

Change-Id: Id028ebcd496563fc77b85700780c572b3cc267f2

lib/config/MWParserEnvironment.js

@@ -370,12 +370,17 @@ MWParserEnvironment.prototype.initializeForPageName = function(pageName, dontRes
 	var title = this.makeTitleFromURLDecodedStr(pageName);
 	this.page.ns = title.getNamespace()._id;
 	this.page.title = title;
-	this.page.titleURI = this.makeLink(title);
 	this.page.name = pageName;
+
 	// Always prefix a ./ so that we don't have to escape colons. Those
 	// would otherwise fool browsers into treating namespaces (like File:)
 	// as protocols.
 	this.page.relativeLinkPrefix = "./";
+
+	// makeLink uses the relative link prefix => this should always
+	// be done after that initialization.
+	this.page.titleURI = this.makeLink(title);
+
 	if (!dontReset) {
 		this.initUID();
 	}

tests/mocha/regression.specs.js

@@ -0,0 +1,35 @@
+'use strict';
+/*global describe, it*/
+
+require('../../core-upgrade.js');
+require("chai").should();
+var ParsoidConfig = require('../../lib/config/ParsoidConfig.js').ParsoidConfig;
+var helpers = require('./test.helpers.js');
+
+// FIXME: MWParserEnvironment.getParserEnv and switchToConfig both require
+// mwApiMap to be setup. This forces us to load WMF config. Fixing this
+// will require some changes to ParsoidConfig and MWParserEnvironment.
+var parsoidConfig = new ParsoidConfig(null, { loadWMF: true, defaultWiki: 'enwiki' });
+var parse = function(src, options) {
+	return helpers.parse(parsoidConfig, src, options).then(function(ret) {
+		return ret.doc;
+	});
+};
+
+// These are regression specs for when we fix bugs that cannot be easily
+// verified with the parser tests framework
+describe('Regression Specs', function() {
+
+	// Wikilinks use ./ prefixed urls. For reasons of consistency,
+	// we should use a similar format for internal cite urls.
+	// This spec ensures that we don't inadvertently break that requirement.
+	it('should use ./ prefixed urls for cite links', function() {
+		return parse('a [[Foo]] <ref>b</ref>').then(function(result) {
+			result.body.querySelector(".mw-ref a").getAttribute('href').
+				should.equal('./Main_Page#cite_note-1');
+			result.body.querySelector("#cite_note-1 a").getAttribute('href').
+				should.equal('./Main_Page#cite_ref-1');
+		});
+	});
+
+});