From ab68df9af087ac8fa0261a5de4c0d5a383de229c Mon Sep 17 00:00:00 2001
From: Claire <claire.github-309c@sitedethib.com>
Date: Fri, 27 Oct 2023 16:04:51 +0200
Subject: [PATCH] Fix hashtag matching pattern matching some URLs (#27584)

---
 app/models/tag.rb       | 2 +-
 spec/models/tag_spec.rb | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/app/models/tag.rb b/app/models/tag.rb
index 8dbcf6f31..dcf8f9c78 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -33,7 +33,7 @@ class Tag < ApplicationRecord
   HASTAG_LAST_SEQUENCE = '([[:word:]_]*[[:alpha:]][[:word:]_]*)'
   HASHTAG_NAME_PAT = "#{HASHTAG_FIRST_SEQUENCE}|#{HASTAG_LAST_SEQUENCE}"
 
-  HASHTAG_RE = %r{(?<![=/)[:word]])#(#{HASHTAG_NAME_PAT})}i
+  HASHTAG_RE = %r{(?<![=/)\w])#(#{HASHTAG_NAME_PAT})}i
   HASHTAG_NAME_RE = /\A(#{HASHTAG_NAME_PAT})\z/i
   HASHTAG_INVALID_CHARS_RE = /[^[:alnum:]#{HASHTAG_SEPARATORS}]/
 
diff --git a/spec/models/tag_spec.rb b/spec/models/tag_spec.rb
index f5cef71b3..19ff69559 100644
--- a/spec/models/tag_spec.rb
+++ b/spec/models/tag_spec.rb
@@ -31,6 +31,10 @@ RSpec.describe Tag do
       expect(subject.match('https://en.wikipedia.org/wiki/Ghostbusters_(song)#Lawsuit')).to be_nil
     end
 
+    it 'does not match URLs with hashtag-like anchors after a numeral' do
+      expect(subject.match('https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111895#c4')).to be_nil
+    end
+
     it 'does not match URLs with hashtag-like anchors after an empty query parameter' do
       expect(subject.match('https://en.wikipedia.org/wiki/Ghostbusters_(song)?foo=#Lawsuit')).to be_nil
     end