Fix project hashtag regexp to stop matching terminal periods

Summary:
Fixes T6416. The comment is consistent with intent, but the actual regexp doesn't quite work right. In particular, we incorrectly match `#security.` as `security.` (with a period) instead of `security` (with no period).

Since this stuff is a pain to test and I evidently got it wrong in this case in D8703, make it unit testable.

Test Plan:
Added unit tests. Also:

{F227181}

Reviewers: chad, btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T6416

Differential Revision: https://secure.phabricator.com/D10753

src/__phutil_library_map__.php

@@ -2823,6 +2823,7 @@ phutil_register_library_map(array(
     'ProjectCreateProjectsCapability' => 'applications/project/capability/ProjectCreateProjectsCapability.php',
     'ProjectQueryConduitAPIMethod' => 'applications/project/conduit/ProjectQueryConduitAPIMethod.php',
     'ProjectRemarkupRule' => 'applications/project/remarkup/ProjectRemarkupRule.php',
+    'ProjectRemarkupRuleTestCase' => 'applications/project/remarkup/__tests__/ProjectRemarkupRuleTestCase.php',
     'QueryFormattingTestCase' => 'infrastructure/storage/__tests__/QueryFormattingTestCase.php',
     'ReleephAuthorFieldSpecification' => 'applications/releeph/field/specification/ReleephAuthorFieldSpecification.php',
     'ReleephBranch' => 'applications/releeph/storage/ReleephBranch.php',
@@ -6015,6 +6016,7 @@ phutil_register_library_map(array(
     'ProjectCreateProjectsCapability' => 'PhabricatorPolicyCapability',
     'ProjectQueryConduitAPIMethod' => 'ProjectConduitAPIMethod',
     'ProjectRemarkupRule' => 'PhabricatorObjectRemarkupRule',
+    'ProjectRemarkupRuleTestCase' => 'PhabricatorTestCase',
     'QueryFormattingTestCase' => 'PhabricatorTestCase',
     'ReleephAuthorFieldSpecification' => 'ReleephFieldSpecification',
     'ReleephBranch' => array(

src/applications/project/remarkup/ProjectRemarkupRule.php

@@ -30,7 +30,7 @@ final class ProjectRemarkupRule extends PhabricatorObjectRemarkupRule {
     // In other contexts, the PhabricatorProjectProjectPHIDType pattern is
     // controlling and these names should parse correctly.
 
-    return '[^\s.!,:;{}#]*[^\s\d!,:;{}#]+(?:[^\s.!,:;{}#][^\s!,:;{}#]*)*';
+    return '[^\s.\d!,:;{}#]+(?:[^\s!,:;{}#][^\s.!,:;{}#]+)*';
   }
 
   protected function loadObjects(array $ids) {

src/applications/project/remarkup/__tests__/ProjectRemarkupRuleTestCase.php

@@ -0,0 +1,57 @@
+<?php
+
+final class ProjectRemarkupRuleTestCase extends PhabricatorTestCase {
+
+  public function testProjectObjectRemarkup() {
+    $cases = array(
+      'I like #ducks.' => array(
+        'embed' => array(),
+        'ref' => array(
+          array(
+            'offset' => 8,
+            'id' => 'ducks',
+          ),
+        ),
+      ),
+      'We should make a post on #blog.example.com tomorrow.' => array(
+        'embed' => array(),
+        'ref' => array(
+          array(
+            'offset' => 26,
+            'id' => 'blog.example.com',
+          ),
+        ),
+      ),
+      'We should make a post on #blog.example.com.' => array(
+        'embed' => array(),
+        'ref' => array(
+          array(
+            'offset' => 26,
+            'id' => 'blog.example.com',
+          ),
+        ),
+      ),
+      '#123' => array(
+        'embed' => array(),
+        'ref' => array(),
+      ),
+      '#security#123' => array(
+        'embed' => array(),
+        'ref' => array(
+          array(
+            'offset' => 1,
+            'id' => 'security',
+            'tail' => '123',
+          ),
+        ),
+      ),
+    );
+
+    foreach ($cases as $input => $expect) {
+      $rule = new ProjectRemarkupRule();
+      $matches = $rule->extractReferences($input);
+      $this->assertEqual($expect, $matches, $input);
+    }
+  }
+
+}

src/infrastructure/markup/rule/PhabricatorObjectRemarkupRule.php

@@ -95,15 +95,33 @@ abstract class PhabricatorObjectRemarkupRule extends PhutilRemarkupRule {
   }
 
   public function apply($text) {
-    $prefix = $this->getObjectNamePrefix();
-    $prefix = preg_quote($prefix, '@');
-    $id = $this->getObjectIDPattern();
-
     $text = preg_replace_callback(
-      '@\B{'.$prefix.'('.$id.')((?:[^}\\\\]|\\\\.)*)}\B@u',
+      $this->getObjectEmbedPattern(),
       array($this, 'markupObjectEmbed'),
       $text);
 
+    $text = preg_replace_callback(
+      $this->getObjectReferencePattern(),
+      array($this, 'markupObjectReference'),
+      $text);
+
+    return $text;
+  }
+
+  private function getObjectEmbedPattern() {
+    $prefix = $this->getObjectNamePrefix();
+    $prefix = preg_quote($prefix);
+    $id = $this->getObjectIDPattern();
+
+    return '(\B{'.$prefix.'('.$id.')((?:[^}\\\\]|\\\\.)*)}\B)u';
+  }
+
+  private function getObjectReferencePattern() {
+    $prefix = $this->getObjectNamePrefix();
+    $prefix = preg_quote($prefix);
+
+    $id = $this->getObjectIDPattern();
+
     // If the prefix starts with a word character (like "D"), we want to
     // require a word boundary so that we don't match "XD1" as "D1". If the
     // prefix does not start with a word character, we want to require no word
@@ -121,12 +139,55 @@ abstract class PhabricatorObjectRemarkupRule extends PhutilRemarkupRule {
     // The "\b" allows us to link "(abcdef)" or similar without linking things
     // in the middle of words.
 
-    $text = preg_replace_callback(
+    return '((?<![#-])'.$boundary.$prefix.'('.$id.')(?:#([-\w\d]+))?(?!\w))u';
-      '((?<![#-])'.$boundary.$prefix.'('.$id.')(?:#([-\w\d]+))?(?!\w))u',
+  }
-      array($this, 'markupObjectReference'),
-      $text);
 
-    return $text;
+
+  /**
+   * Extract matched object references from a block of text.
+   *
+   * This is intended to make it easy to write unit tests for object remarkup
+   * rules. Production code is not normally expected to call this method.
+   *
+   * @param   string  Text to match rules against.
+   * @return  wild    Matches, suitable for writing unit tests against.
+   */
+  public function extractReferences($text) {
+    $embed_matches = null;
+    preg_match_all(
+      $this->getObjectEmbedPattern(),
+      $text,
+      $embed_matches,
+      PREG_OFFSET_CAPTURE | PREG_SET_ORDER);
+
+    $ref_matches = null;
+    preg_match_all(
+      $this->getObjectReferencePattern(),
+      $text,
+      $ref_matches,
+      PREG_OFFSET_CAPTURE | PREG_SET_ORDER);
+
+    $results = array();
+    $sets = array(
+      'embed' => $embed_matches,
+      'ref' => $ref_matches,
+    );
+    foreach ($sets as $type => $matches) {
+      $formatted = array();
+      foreach ($matches as $match) {
+        $format = array(
+          'offset' => $match[1][1],
+          'id' => $match[1][0],
+        );
+        if (isset($match[2][0])) {
+          $format['tail'] = $match[2][0];
+        }
+        $formatted[] = $format;
+      }
+      $results[$type] = $formatted;
+    }
+
+    return $results;
   }
 
   public function markupObjectEmbed($matches) {