Issue tracker does not filter WIP tickets properly

Summary

(Summarize the bug encountered concisely)

On our private locally installed Gitlab CE instance, we are using filtering to filter for Issues that are WIP. These are marked with WIP. The filtering is not working as it should be as it does not properly apply boolean logic.

Steps to reproduce

Searching for WIP != Yes

Searching for WIP = No

should produce the same result in my understanding, however using '!=' is not working as intended.

What is the current bug behavior?

The filtering in query expressions is not working as intented when using != expression

What is the expected correct behavior?

Filtering '!= yes' should result in the same results as '= no'

Relevant logs and/or screenshots

The screenshots have been pasted to the Steps to reproduce section.

Output of checks

(If you are reporting a bug on GitLab.com, write: This bug happens on GitLab.com)

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:		Ubuntu 16.04
Current User:	git
Using RVM:	no
Ruby Version:	2.6.6p146
Gem Version:	2.7.10
Bundler Version:1.17.3
Rake Version:	12.3.3
Redis Version:	5.0.9
Git Version:	2.26.2
Sidekiq Version:5.2.7
Go Version:	unknown

GitLab information
Version:	13.0.3
Revision:	e2397fc2acb
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	PostgreSQL
DB Version:	11.7
URL:		
HTTP Clone URL:	
SSH Clone URL:	
Using LDAP:	no
Using Omniauth:	yes
Omniauth Providers: 

GitLab Shell
Version:	13.2.0
Repository storage paths:
- default: 	/var/opt/gitlab/git-data/repositories
GitLab Shell path:		/opt/gitlab/embedded/service/gitlab-shell
Git:		/opt/gitlab/embedded/bin/git

Results of GitLab application Check

Expand for output related to the GitLab application check

sudo gitlab-rake gitlab:check SANITIZE=true
Checking GitLab subtasks ...
Checking GitLab Shell ...
GitLab Shell: ... GitLab Shell version >= 13.2.0 ? ... OK (13.2.0)
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Internal API available: OK
Redis available via internal API: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Gitaly ...
Gitaly: ... default ... OK
Checking Gitaly ... Finished
Checking Sidekiq ...
Sidekiq: ... Running? ... yes
Number of Sidekiq processes ... 1
Checking Sidekiq ... Finished
Checking Incoming Email ...
Incoming Email: ... Reply by email is disabled in config/gitlab.yml
Checking Incoming Email ... Finished
Checking LDAP ...
LDAP: ... LDAP is disabled in config/gitlab.yml
Checking LDAP ... Finished
Checking GitLab App ...
Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... yes
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ...
12/7 ... yes
12/8 ... yes
12/9 ... yes
12/10 ... yes
12/11 ... yes
15/12 ... yes
12/13 ... yes
15/14 ... yes
12/15 ... yes
12/16 ... yes
12/17 ... yes
12/18 ... yes
19/19 ... yes
19/20 ... yes
19/21 ... yes
19/22 ... yes
19/23 ... yes
19/24 ... yes
21/25 ... yes
19/27 ... yes
20/28 ... yes
27/29 ... yes
19/30 ... yes
19/31 ... yes
19/32 ... yes
15/34 ... yes
12/35 ... yes
20/36 ... yes
15/37 ... yes
23/38 ... yes
20/39 ... yes
19/40 ... yes
19/41 ... yes
19/42 ... yes
19/43 ... yes
19/44 ... yes
15/45 ... yes
19/46 ... yes
19/47 ... yes
27/48 ... yes
27/49 ... yes
12/50 ... yes
12/51 ... yes
24/52 ... yes
19/53 ... yes
9/54 ... yes
15/55 ... yes
12/56 ... yes
15/57 ... yes
28/58 ... yes
28/59 ... yes
26/60 ... yes
26/61 ... yes
15/62 ... yes
15/63 ... yes
25/64 ... yes
Redis version >= 4.0.0? ... yes
Ruby version >= 2.5.3 ? ... yes (2.6.6)
Git version >= 2.22.0 ? ... yes (2.26.2)
Git user has default SSH configuration? ... yes
Active users: ... 9
Is authorized keys file accessible? ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... no
Try fixing it:
Please migrate all projects to hashed storage
as legacy storage is deprecated in 13.0 and support will be removed in 14.0.
For more information see:
doc/administration/repository_storage_types.md
Checking GitLab App ... Finished
Checking GitLab subtasks ... Finished

Possible fixes

For mitigation we use only boolean expressions with true. Maybe the expression could be changed internally so that != Yes would use = true