Persist "Show Changeset" and improve path text selection

Summary:
Ref T13513. Currently:

  - If you click the "Show Changeset" button, your state change doesn't actually get saved on the server.
  - It's hard to select a changeset path name for copy/paste because the "highlight the header" code tends to eat the event.

Instead: persist the former event; make the actual path text not be part of the highlight hitbox.

Test Plan:
  - Clicked "Show Changeset", reloaded, saw changeset visibility persisted.
  - Selected changeset path text without issues.
  - Clicked non-text header area to select/deselect changesets.

Maniphest Tasks: T13513

Differential Revision: https://secure.phabricator.com/D21236

resources/celerity/map.php

@@ -12,8 +12,8 @@ return array(
     'core.pkg.css' => '1b80c45d',
     'core.pkg.js' => '1e667bcb',
     'dark-console.pkg.js' => '187792c2',
-    'differential.pkg.css' => '2d70b7b9',
+    'differential.pkg.css' => 'd71d4531',
-    'differential.pkg.js' => 'faa6e8ab',
+    'differential.pkg.js' => 'cf4f3263',
     'diffusion.pkg.css' => '42c75c37',
     'diffusion.pkg.js' => 'a98c0bf7',
     'maniphest.pkg.css' => '35995d6d',
@@ -63,7 +63,7 @@ return array(
     'rsrc/css/application/diff/diff-tree-view.css' => 'e2d3e222',
     'rsrc/css/application/diff/inline-comment-summary.css' => '81eb368d',
     'rsrc/css/application/differential/add-comment.css' => '7e5900d9',
-    'rsrc/css/application/differential/changeset-view.css' => '5fb26c90',
+    'rsrc/css/application/differential/changeset-view.css' => 'a5cc67cf',
     'rsrc/css/application/differential/core.css' => '7300a73e',
     'rsrc/css/application/differential/phui-inline-comment.css' => '48acce5b',
     'rsrc/css/application/differential/revision-comment.css' => '7dbc8d1d',
@@ -379,7 +379,7 @@ return array(
     'rsrc/js/application/dashboard/behavior-dashboard-move-panels.js' => 'a2ab19be',
     'rsrc/js/application/dashboard/behavior-dashboard-query-panel-select.js' => '1e413dc9',
     'rsrc/js/application/dashboard/behavior-dashboard-tab-panel.js' => '0116d3e8',
-    'rsrc/js/application/diff/DiffChangeset.js' => 'a49dc31e',
+    'rsrc/js/application/diff/DiffChangeset.js' => '700bf848',
     'rsrc/js/application/diff/DiffChangesetList.js' => '6992b85c',
     'rsrc/js/application/diff/DiffInline.js' => 'db754a7b',
     'rsrc/js/application/diff/DiffPathView.js' => '8207abf9',
@@ -560,7 +560,7 @@ return array(
     'conpherence-transaction-css' => '3a3f5e7e',
     'd3' => '9d068042',
     'diff-tree-view-css' => 'e2d3e222',
-    'differential-changeset-view-css' => '5fb26c90',
+    'differential-changeset-view-css' => 'a5cc67cf',
     'differential-core-view-css' => '7300a73e',
     'differential-revision-add-comment-css' => '7e5900d9',
     'differential-revision-comment-css' => '7dbc8d1d',
@@ -776,7 +776,7 @@ return array(
     'phabricator-darklog' => '3b869402',
     'phabricator-darkmessage' => '26cd4b73',
     'phabricator-dashboard-css' => '5a205b9d',
-    'phabricator-diff-changeset' => 'a49dc31e',
+    'phabricator-diff-changeset' => '700bf848',
     'phabricator-diff-changeset-list' => '6992b85c',
     'phabricator-diff-inline' => 'db754a7b',
     'phabricator-diff-path-view' => '8207abf9',
@@ -1489,9 +1489,6 @@ return array(
     '5faf27b9' => array(
       'phuix-form-control-view',
     ),
-    '5fb26c90' => array(
-      'phui-inline-comment-view-css',
-    ),
     '60cd9241' => array(
       'javelin-behavior',
     ),
@@ -1555,6 +1552,19 @@ return array(
       'javelin-install',
       'javelin-util',
     ),
+    '700bf848' => array(
+      'javelin-dom',
+      'javelin-util',
+      'javelin-stratcom',
+      'javelin-install',
+      'javelin-workflow',
+      'javelin-router',
+      'javelin-behavior-device',
+      'javelin-vector',
+      'phabricator-diff-inline',
+      'phabricator-diff-path-view',
+      'phuix-button-view',
+    ),
     70245195 => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -1853,19 +1863,6 @@ return array(
       'javelin-stratcom',
       'javelin-vector',
     ),
-    'a49dc31e' => array(
-      'javelin-dom',
-      'javelin-util',
-      'javelin-stratcom',
-      'javelin-install',
-      'javelin-workflow',
-      'javelin-router',
-      'javelin-behavior-device',
-      'javelin-vector',
-      'phabricator-diff-inline',
-      'phabricator-diff-path-view',
-      'phuix-button-view',
-    ),
     'a4aa75c4' => array(
       'phui-button-css',
       'phui-button-simple-css',
@@ -1874,6 +1871,9 @@ return array(
       'javelin-install',
       'javelin-dom',
     ),
+    'a5cc67cf' => array(
+      'phui-inline-comment-view-css',
+    ),
     'a77e2cbd' => array(
       'javelin-behavior',
       'javelin-stratcom',

src/applications/differential/view/DifferentialChangesetDetailView.php

@@ -278,7 +278,13 @@ final class DifferentialChangesetDetailView extends AphrontView {
           ),
           array(
             $icon,
-            $display_filename,
+            javelin_tag(
+              'span',
+              array(
+                'class' => 'differential-changeset-path-name',
+                'sigil' => 'changeset-header-path-name',
+              ),
+              $display_filename),
           )),
         javelin_tag(
           'div',

webroot/rsrc/css/application/differential/changeset-view.css

@@ -319,6 +319,11 @@ td.cov-I {
   cursor: pointer;
 }
 
+.differential-changeset .differential-file-icon-header
+  .differential-changeset-path-name {
+  cursor: auto;
+}
+
 .device-phone .differential-changeset .differential-file-icon-header {
   word-break: break-word;
   margin-right: 8px;

webroot/rsrc/js/application/diff/DiffChangeset.js

@@ -886,6 +886,13 @@ JX.install('DiffChangeset', {
     },
 
     _onClickHeader: function(e) {
+      // If the user clicks the actual path name text, don't count this as
+      // a selection action: we want to let them select the path.
+      var path_name = e.getNode('changeset-header-path-name');
+      if (path_name) {
+        return;
+      }
+
       e.prevent();
 
       if (this._isSelected) {
@@ -986,18 +993,16 @@ JX.install('DiffChangeset', {
 
     _onClickShowButton: function(e) {
       e.prevent();
-      this.setVisible(true);
+
+      // We're always showing the changeset, but want to make sure the state
+      // change is persisted on the server.
+      this.toggleVisibility();
     },
 
     isVisible: function() {
       return this._visible;
     },
 
-    _onundo: function(e) {
-      e.kill();
-      this.toggleVisibility();
-    },
-
     getPathView: function() {
       if (!this._pathView) {
         var view = new JX.DiffPathView()