Strip whitespace from username/login value for user lookup

As per the discussion with @psimyn, this change does not affect the frontend, so user input will not be validated on the signin screen.

Instead, the value sent to the backend has leading and trailing whitespace stripped before looking up the user with find_by.

Closes #42637

3 files changed, 14 insertions, 1 deletions

diff --git a/app/models/user.rb b/app/models/user.rb
index 4097fe2b5dc..5e84d2da805 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -249,7 +249,7 @@ class User < ActiveRecord::Base
     def find_for_database_authentication(warden_conditions)
       conditions = warden_conditions.dup
       if login = conditions.delete(:login)
-        where(conditions).find_by("lower(username) = :value OR lower(email) = :value", value: login.downcase)
+        where(conditions).find_by("lower(username) = :value OR lower(email) = :value", value: login.downcase.strip)
       else
         find_by(conditions)
       end
diff --git a/changelogs/unreleased/change-strip-whitespace-from-username-input-42637.yml b/changelogs/unreleased/change-strip-whitespace-from-username-input-42637.yml
new file mode 100644
index 00000000000..a51781396ee
--- /dev/null
+++ b/changelogs/unreleased/change-strip-whitespace-from-username-input-42637.yml
@@ -0,0 +1,5 @@
+---
+title: Remove whitespace from the username/email sign in form field
+merge_request: 17020
+author: Peter lauck
+type: changed
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 76a6aef39cc..1815696a8a0 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -893,6 +893,14 @@ describe User do
     end
   end
 
+  describe '.find_for_database_authentication' do
+    it 'strips whitespace from login' do
+      user = create(:user)
+
+      expect(described_class.find_for_database_authentication({ login: " #{user.username} " })).to eq user
+    end
+  end
+
   describe '.find_by_any_email' do
     it 'finds by primary email' do
       user = create(:user, email: 'foo@example.com')