Merge branch '42800-change-usage-of-avatar_icon' into 'master'

Change all occurrences of ApplicationHelper#avatar_icon to use a User object where possible

Closes #42800

See merge request gitlab-org/gitlab-ce!16976

35 files changed, 127 insertions, 59 deletions

diff --git a/app/finders/issues_finder.rb b/app/finders/issues_finder.rb
index 98831f5be4a..83245aadf6e 100644
--- a/app/finders/issues_finder.rb
+++ b/app/finders/issues_finder.rb
@@ -21,7 +21,7 @@ class IssuesFinder < IssuableFinder
   CONFIDENTIAL_ACCESS_LEVEL = Gitlab::Access::REPORTER
 
   def klass
-    Issue
+    Issue.includes(:author)
   end
 
   def with_confidentiality_access_check
diff --git a/app/finders/notes_finder.rb b/app/finders/notes_finder.rb
index 12157818bcd..33ee1e975b9 100644
--- a/app/finders/notes_finder.rb
+++ b/app/finders/notes_finder.rb
@@ -57,7 +57,7 @@ class NotesFinder
     types = %w(commit issue merge_request snippet)
     note_relations = types.map { |t| notes_for_type(t) }
     note_relations.map! { |notes| search(notes) }
-    UnionFinder.new.find_union(note_relations, Note)
+    UnionFinder.new.find_union(note_relations, Note.includes(:author))
   end
 
   def noteables_for_type(noteable_type)
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 6530327698b..a6011eb9f30 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -68,18 +68,32 @@ module ApplicationHelper
     end
   end
 
-  def avatar_icon(user_or_email = nil, size = nil, scale = 2, only_path: true)
-    user =
-      if user_or_email.is_a?(User)
-        user_or_email
-      else
-        User.find_by_any_email(user_or_email.try(:downcase))
-      end
+  # Takes both user and email and returns the avatar_icon by
+  # user (preferred) or email.
+  def avatar_icon_for(user = nil, email = nil, size = nil, scale = 2, only_path: true)
+    if user
+      avatar_icon_for_user(user, size, scale, only_path: only_path)
+    elsif email
+      avatar_icon_for_email(email, size, scale, only_path: only_path)
+    else
+      default_avatar
+    end
+  end
+
+  def avatar_icon_for_email(email = nil, size = nil, scale = 2, only_path: true)
+    user = User.find_by_any_email(email.try(:downcase))
+    if user
+      avatar_icon_for_user(user, size, scale, only_path: only_path)
+    else
+      gravatar_icon(email, size, scale)
+    end
+  end
 
+  def avatar_icon_for_user(user = nil, size = nil, scale = 2, only_path: true)
     if user
       user.avatar_url(size: size, only_path: only_path) || default_avatar
     else
-      gravatar_icon(user_or_email, size, scale)
+      gravatar_icon(nil, size, scale)
     end
   end
 
diff --git a/app/helpers/avatars_helper.rb b/app/helpers/avatars_helper.rb
index be11d453898..21b6c0a8ad5 100644
--- a/app/helpers/avatars_helper.rb
+++ b/app/helpers/avatars_helper.rb
@@ -8,10 +8,22 @@ module AvatarsHelper
     }))
   end
 
+  def user_avatar_url_for(options = {})
+    if options[:url]
+      options[:url]
+    elsif options[:user]
+      avatar_icon_for_user(options[:user], options[:size])
+    else
+      avatar_icon_for_email(options[:user_email], options[:size])
+    end
+  end
+
   def user_avatar_without_link(options = {})
     avatar_size = options[:size] || 16
     user_name = options[:user].try(:name) || options[:user_name]
-    avatar_url = options[:url] || avatar_icon(options[:user] || options[:user_email], avatar_size)
+
+    avatar_url = user_avatar_url_for(options.merge(size: avatar_size))
+
     has_tooltip = options[:has_tooltip].nil? ? true : options[:has_tooltip]
     data_attributes = options[:data] || {}
     css_class = %W[avatar s#{avatar_size}].push(*options[:css_class])
diff --git a/app/helpers/namespaces_helper.rb b/app/helpers/namespaces_helper.rb
index b78d3072186..40ca666f1bf 100644
--- a/app/helpers/namespaces_helper.rb
+++ b/app/helpers/namespaces_helper.rb
@@ -33,7 +33,7 @@ module NamespacesHelper
     if namespace.is_a?(Group)
       group_icon(namespace)
     else
-      avatar_icon(namespace.owner.email, size)
+      avatar_icon_for_user(namespace.owner, size)
     end
   end
 
diff --git a/app/helpers/projects_helper.rb b/app/helpers/projects_helper.rb
index 43c8b1b612b..b97b72d62c3 100644
--- a/app/helpers/projects_helper.rb
+++ b/app/helpers/projects_helper.rb
@@ -19,7 +19,7 @@ module ProjectsHelper
     classes = %W[avatar avatar-inline s#{opts[:size]}]
     classes << opts[:avatar_class] if opts[:avatar_class]
 
-    avatar = avatar_icon(author, opts[:size])
+    avatar = avatar_icon_for_user(author, opts[:size])
     src = opts[:lazy_load] ? nil : avatar
 
     image_tag(src, width: opts[:size], class: classes, alt: '', "data-src" => avatar)
diff --git a/app/views/admin/users/_user.html.haml b/app/views/admin/users/_user.html.haml
index 3b85586e45b..bbfeceff5b9 100644
--- a/app/views/admin/users/_user.html.haml
+++ b/app/views/admin/users/_user.html.haml
@@ -1,6 +1,6 @@
 %li.flex-row
   .user-avatar
-    = image_tag avatar_icon(user), class: "avatar", alt: ''
+    = image_tag avatar_icon_for_user(user), class: "avatar", alt: ''
   .row-main-content
     .user-name.row-title.str-truncated-100
       = link_to user.name, [:admin, user]
diff --git a/app/views/admin/users/show.html.haml b/app/views/admin/users/show.html.haml
index 101667508a9..ec3be869797 100644
--- a/app/views/admin/users/show.html.haml
+++ b/app/views/admin/users/show.html.haml
@@ -10,7 +10,7 @@
         = @user.name
       %ul.well-list
         %li
-          = image_tag avatar_icon(@user, 60), class: "avatar s60"
+          = image_tag avatar_icon_for_user(@user, 60), class: "avatar s60"
         %li
           %span.light Profile page:
           %strong
diff --git a/app/views/discussions/_discussion.html.haml b/app/views/discussions/_discussion.html.haml
index 205320ed87c..8b9fa3d6b05 100644
--- a/app/views/discussions/_discussion.html.haml
+++ b/app/views/discussions/_discussion.html.haml
@@ -3,7 +3,7 @@
   .timeline-entry-inner
     .timeline-icon
       = link_to user_path(discussion.author) do
-        = image_tag avatar_icon(discussion.author), class: "avatar s40"
+        = image_tag avatar_icon_for_user(discussion.author), class: "avatar s40"
     .timeline-content
       .discussion.js-toggle-container{ data: { discussion_id: discussion.id } }
         .discussion-header
diff --git a/app/views/events/_event.atom.builder b/app/views/events/_event.atom.builder
index 38741fe6662..d56234e6c1a 100644
--- a/app/views/events/_event.atom.builder
+++ b/app/views/events/_event.atom.builder
@@ -10,7 +10,7 @@ xml.entry do
   # eager-loaded. This allows us to re-use the user object's Email address,
   # instead of having to run additional queries to figure out what Email to use
   # for the avatar.
-  xml.media   :thumbnail, width: "40", height: "40", url: image_url(avatar_icon(event.author))
+  xml.media   :thumbnail, width: "40", height: "40", url: image_url(avatar_icon_for_user(event.author))
 
   xml.author do
     xml.username event.author_username
diff --git a/app/views/help/ui.html.haml b/app/views/help/ui.html.haml
index 445f0dffbcc..1c4d67a8d2c 100644
--- a/app/views/help/ui.html.haml
+++ b/app/views/help/ui.html.haml
@@ -68,7 +68,7 @@
   .example
     .cover-block
       .avatar-holder
-        = image_tag avatar_icon('admin@example.com', 90), class: "avatar s90", alt: ''
+        = image_tag avatar_icon_for_email('admin@example.com', 90), class: "avatar s90", alt: ''
       .cover-title
         John Smith
 
diff --git a/app/views/issues/_issue.atom.builder b/app/views/issues/_issue.atom.builder
index 0c113c08526..21cf6d0dd65 100644
--- a/app/views/issues/_issue.atom.builder
+++ b/app/views/issues/_issue.atom.builder
@@ -3,7 +3,7 @@ xml.entry do
   xml.link    href: project_issue_url(issue.project, issue)
   xml.title   truncate(issue.title, length: 80)
   xml.updated issue.updated_at.xmlschema
-  xml.media   :thumbnail, width: "40", height: "40", url: image_url(avatar_icon(issue.author_email))
+  xml.media   :thumbnail, width: "40", height: "40", url: image_url(avatar_icon_for_user(issue.author))
 
   xml.author do
     xml.name issue.author_name
diff --git a/app/views/layouts/header/_default.html.haml b/app/views/layouts/header/_default.html.haml
index e7fc83a8d04..1d00ae928f6 100644
--- a/app/views/layouts/header/_default.html.haml
+++ b/app/views/layouts/header/_default.html.haml
@@ -45,7 +45,7 @@
                   = todos_count_format(todos_pending_count)
             %li.header-user.dropdown
               = link_to current_user, class: user_dropdown_class, data: { toggle: "dropdown" } do
-                = image_tag avatar_icon(current_user, 23), width: 23, height: 23, class: "header-user-avatar qa-user-avatar"
+                = image_tag avatar_icon_for_user(current_user, 23), width: 23, height: 23, class: "header-user-avatar qa-user-avatar"
                 = sprite_icon('angle-down', css_class: 'caret-down')
               .dropdown-menu-nav.dropdown-menu-align-right
                 %ul
diff --git a/app/views/notify/pipeline_failed_email.html.haml b/app/views/notify/pipeline_failed_email.html.haml
index 8eb3f2d5192..38dab104eb5 100644
--- a/app/views/notify/pipeline_failed_email.html.haml
+++ b/app/views/notify/pipeline_failed_email.html.haml
@@ -60,7 +60,7 @@
               %tbody
                 %tr
                   %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;padding-right:5px;" }
-                    %img.avatar{ height: "24", src: avatar_icon(commit.author || commit.author_email, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
+                    %img.avatar{ height: "24", src: avatar_icon_for(commit.author, commit.author_email, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
                   %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;" }
                     - if commit.author
                       %a.muted{ href: user_url(commit.author), style: "color:#333333;text-decoration:none;" }
@@ -76,7 +76,7 @@
                 %tbody
                   %tr
                     %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;padding-right:5px;" }
-                      %img.avatar{ height: "24", src: avatar_icon(commit.committer || commit.committer_email, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
+                      %img.avatar{ height: "24", src: avatar_icon_for(commit.committer, commit.committer_email, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
                     %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;" }
                       - if commit.committer
                         %a.muted{ href: user_url(commit.committer), style: "color:#333333;text-decoration:none;" }
@@ -100,7 +100,7 @@
             triggered by
           - if @pipeline.user
             %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;padding-right:5px;padding-left:5px", width: "24" }
-              %img.avatar{ height: "24", src: avatar_icon(@pipeline.user, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
+              %img.avatar{ height: "24", src: avatar_icon_for_user(@pipeline.user, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
             %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;font-weight:500;line-height:1.4;vertical-align:baseline;" }
               %a.muted{ href: user_url(@pipeline.user), style: "color:#333333;text-decoration:none;" }
                 = @pipeline.user.name
diff --git a/app/views/notify/pipeline_success_email.html.haml b/app/views/notify/pipeline_success_email.html.haml
index bae37292d62..7b06e8afa0b 100644
--- a/app/views/notify/pipeline_success_email.html.haml
+++ b/app/views/notify/pipeline_success_email.html.haml
@@ -60,7 +60,7 @@
               %tbody
                 %tr
                   %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;padding-right:5px;" }
-                    %img.avatar{ height: "24", src: avatar_icon(commit.author || commit.author_email, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
+                    %img.avatar{ height: "24", src: avatar_icon_for(commit.author, commit.author_email, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
                   %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;" }
                     - if commit.author
                       %a.muted{ href: user_url(commit.author), style: "color:#333333;text-decoration:none;" }
@@ -76,7 +76,7 @@
                 %tbody
                   %tr
                     %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;padding-right:5px;" }
-                      %img.avatar{ height: "24", src: avatar_icon(commit.committer || commit.committer_email, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
+                      %img.avatar{ height: "24", src: avatar_icon_for(commit.committer, commit.committer_email, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
                     %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;" }
                       - if commit.committer
                         %a.muted{ href: user_url(commit.committer), style: "color:#333333;text-decoration:none;" }
@@ -100,7 +100,7 @@
             triggered by
           - if @pipeline.user
             %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;line-height:1.4;vertical-align:middle;padding-right:5px;padding-left:5px", width: "24" }
-              %img.avatar{ height: "24", src: avatar_icon(@pipeline.user, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
+              %img.avatar{ height: "24", src: avatar_icon_for_user(@pipeline.user, 24, only_path: false), style: "display:block;border-radius:12px;margin:-2px 0;", width: "24", alt: "" }/
             %td{ style: "font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:15px;font-weight:500;line-height:1.4;vertical-align:baseline;" }
               %a.muted{ href: user_url(@pipeline.user), style: "color:#333333;text-decoration:none;" }
                 = @pipeline.user.name
diff --git a/app/views/profiles/show.html.haml b/app/views/profiles/show.html.haml
index 5c76d2d8f51..110736dc557 100644
--- a/app/views/profiles/show.html.haml
+++ b/app/views/profiles/show.html.haml
@@ -20,8 +20,8 @@
             or change it at #{link_to Gitlab.config.gravatar.host, 'https://' + Gitlab.config.gravatar.host}
     .col-lg-8
       .clearfix.avatar-image.append-bottom-default
-        = link_to avatar_icon(@user, 400), target: '_blank', rel: 'noopener noreferrer' do
-          = image_tag avatar_icon(@user, 160), alt: '', class: 'avatar s160'
+        = link_to avatar_icon_for_user(@user, 400), target: '_blank', rel: 'noopener noreferrer' do
+          = image_tag avatar_icon_for_user(@user, 160), alt: '', class: 'avatar s160'
       %h5.prepend-top-0= _("Upload new avatar")
       .prepend-top-5.append-bottom-10
         %button.btn.js-choose-user-avatar-button{ type: 'button' }= _("Choose file...")
diff --git a/app/views/projects/commits/_commit.atom.builder b/app/views/projects/commits/_commit.atom.builder
index 04914888763..50f7e7a3a33 100644
--- a/app/views/projects/commits/_commit.atom.builder
+++ b/app/views/projects/commits/_commit.atom.builder
@@ -3,7 +3,7 @@ xml.entry do
   xml.link    href: project_commit_url(@project, id: commit.id)
   xml.title   truncate(commit.title, length: 80, escape: false)
   xml.updated commit.committed_date.xmlschema
-  xml.media   :thumbnail, width: "40", height: "40", url: image_url(avatar_icon(commit.author_email))
+  xml.media   :thumbnail, width: "40", height: "40", url: image_url(avatar_icon_for_email(commit.author_email))
 
   xml.author do |author|
     xml.name commit.author_name
diff --git a/app/views/projects/jobs/_user.html.haml b/app/views/projects/jobs/_user.html.haml
index 83f299da651..461d503f95d 100644
--- a/app/views/projects/jobs/_user.html.haml
+++ b/app/views/projects/jobs/_user.html.haml
@@ -1,7 +1,7 @@
 by
 %a{ href: user_path(@build.user) }
   %span.hidden-xs
-    = image_tag avatar_icon(@build.user, 24), class: "avatar s24"
+    = image_tag avatar_icon_for_user(@build.user, 24), class: "avatar s24"
     %strong{ data: { toggle: 'tooltip', placement: 'top', title: @build.user.to_reference } }
       = @build.user.name
   %strong.visible-xs-inline= @build.user.to_reference
diff --git a/app/views/projects/network/show.json.erb b/app/views/projects/network/show.json.erb
index 7491b37310d..a0e82e891ff 100644
--- a/app/views/projects/network/show.json.erb
+++ b/app/views/projects/network/show.json.erb
@@ -9,7 +9,7 @@
         author: {
           name: c.author_name,
           email: c.author_email,
-          icon: image_path(avatar_icon(c.author_email, 20))
+          icon: image_path(avatar_icon_for_email(c.author_email, 20))
         },
         time: c.time,
         space: c.spaces.first,
diff --git a/app/views/projects/pipeline_schedules/_pipeline_schedule.html.haml b/app/views/projects/pipeline_schedules/_pipeline_schedule.html.haml
index a8692b83b07..55d0e8bb7f9 100644
--- a/app/views/projects/pipeline_schedules/_pipeline_schedule.html.haml
+++ b/app/views/projects/pipeline_schedules/_pipeline_schedule.html.haml
@@ -21,7 +21,7 @@
         = s_("PipelineSchedules|Inactive")
     %td
       - if pipeline_schedule.owner
-        = image_tag avatar_icon(pipeline_schedule.owner, 20), class: "avatar s20"
+        = image_tag avatar_icon_for_user(pipeline_schedule.owner, 20), class: "avatar s20"
         = link_to user_path(pipeline_schedule.owner) do
           = pipeline_schedule.owner&.name
     %td
diff --git a/app/views/projects/repositories/_feed.html.haml b/app/views/projects/repositories/_feed.html.haml
index 170f9e259df..87895a15239 100644
--- a/app/views/projects/repositories/_feed.html.haml
+++ b/app/views/projects/repositories/_feed.html.haml
@@ -11,7 +11,7 @@
     %div
       = link_to project_commits_path(@project, commit.id) do
         %code= commit.short_id
-      = image_tag avatar_icon(commit.author_email), class: "", width: 16, alt: ''
+      = image_tag avatar_icon_for_email(commit.author_email), class: "", width: 16, alt: ''
       = markdown(truncate(commit.title, length: 40), pipeline: :single_line, author: commit.author)
   %td
     %span.pull-right.cgray
diff --git a/app/views/search/results/_snippet_blob.html.haml b/app/views/search/results/_snippet_blob.html.haml
index c4a5131c1a7..57a0b64bfd5 100644
--- a/app/views/search/results/_snippet_blob.html.haml
+++ b/app/views/search/results/_snippet_blob.html.haml
@@ -7,7 +7,7 @@
     = snippet.title
     by
     = link_to user_snippets_path(snippet.author) do
-      = image_tag avatar_icon(snippet.author), class: "avatar avatar-inline s16", alt: ''
+      = image_tag avatar_icon_for_user(snippet.author), class: "avatar avatar-inline s16", alt: ''
       = snippet.author_name
     %span.light= time_ago_with_tooltip(snippet.created_at)
   %h4.snippet-title
diff --git a/app/views/search/results/_snippet_title.html.haml b/app/views/search/results/_snippet_title.html.haml
index aef825691e0..65710c09a89 100644
--- a/app/views/search/results/_snippet_title.html.haml
+++ b/app/views/search/results/_snippet_title.html.haml
@@ -18,6 +18,6 @@
     %span
       by
       = link_to user_snippets_path(snippet_title.author) do
-        = image_tag avatar_icon(snippet_title.author), class: "avatar avatar-inline s16", alt: ''
+        = image_tag avatar_icon_for_user(snippet_title.author), class: "avatar avatar-inline s16", alt: ''
         = snippet_title.author_name
       %span.light= time_ago_with_tooltip(snippet_title.created_at)
diff --git a/app/views/shared/members/_member.html.haml b/app/views/shared/members/_member.html.haml
index 71878e93255..ba57d922c6d 100644
--- a/app/views/shared/members/_member.html.haml
+++ b/app/views/shared/members/_member.html.haml
@@ -8,7 +8,7 @@
 %li.member{ class: dom_class(member), id: dom_id(member) }
   %span.list-item-name
     - if user
-      = image_tag avatar_icon(user, 40), class: "avatar s40", alt: ''
+      = image_tag avatar_icon_for_user(user, 40), class: "avatar s40", alt: ''
       .user-info
         = link_to user.name, user_path(user), class: 'member'
         %span.cgray= user.to_reference
@@ -36,7 +36,7 @@
               Expires in #{distance_of_time_in_words_to_now(member.expires_at)}
 
     - else
-      = image_tag avatar_icon(member.invite_email, 40), class: "avatar s40", alt: ''
+      = image_tag avatar_icon_for_email(member.invite_email, 40), class: "avatar s40", alt: ''
       .user-info
         .member= member.invite_email
         .cgray
diff --git a/app/views/shared/milestones/_issuable.html.haml b/app/views/shared/milestones/_issuable.html.haml
index 14395bcc661..479b7270b28 100644
--- a/app/views/shared/milestones/_issuable.html.haml
+++ b/app/views/shared/milestones/_issuable.html.haml
@@ -28,4 +28,4 @@
       - assignees.each do |assignee|
         = link_to polymorphic_path(issuable_type_args, { milestone_title: @milestone.title, assignee_id: assignee.id, state: 'all' }),
                   class: 'has-tooltip', title: "Assigned to #{assignee.name}", data: { container: 'body' } do
-          - image_tag(avatar_icon(assignee, 16), class: "avatar s16", alt: '')
+          - image_tag(avatar_icon_for_user(assignee, 16), class: "avatar s16", alt: '')
diff --git a/app/views/shared/milestones/_participants_tab.html.haml b/app/views/shared/milestones/_participants_tab.html.haml
index 1615871385e..fe83040c168 100644
--- a/app/views/shared/milestones/_participants_tab.html.haml
+++ b/app/views/shared/milestones/_participants_tab.html.haml
@@ -2,7 +2,7 @@
   - users.each do |user|
     %li
       = link_to user, title: user.name, class: "darken" do
-        = image_tag avatar_icon(user, 32), class: "avatar s32"
+        = image_tag avatar_icon_for_user(user, 32), class: "avatar s32"
         %strong= truncate(user.name, length: 40)
         %div
           %small.cgray= user.username
diff --git a/app/views/shared/notes/_note.html.haml b/app/views/shared/notes/_note.html.haml
index 98e0161f7d1..bf359774ead 100644
--- a/app/views/shared/notes/_note.html.haml
+++ b/app/views/shared/notes/_note.html.haml
@@ -16,7 +16,7 @@
         = icon_for_system_note(note)
       - else
         %a.image-diff-avatar-link{ href: user_path(note.author) }
-          = image_tag avatar_icon(note.author), alt: '', class: 'avatar s40'
+          = image_tag avatar_icon_for_user(note.author), alt: '', class: 'avatar s40'
           - if note.is_a?(DiffNote) && note.on_image?
             - if show_image_comment_badge && note_counter == 0
               -# Only show this for the first comment in the discussion
diff --git a/app/views/shared/notes/_notes_with_form.html.haml b/app/views/shared/notes/_notes_with_form.html.haml
index e11f778adf5..b3f865c5b47 100644
--- a/app/views/shared/notes/_notes_with_form.html.haml
+++ b/app/views/shared/notes/_notes_with_form.html.haml
@@ -14,7 +14,7 @@
 
         .timeline-icon.hidden-xs.hidden-sm
           %a.author_link{ href: user_path(current_user) }
-            = image_tag avatar_icon(current_user), alt: current_user.to_reference, class: 'avatar s40'
+            = image_tag avatar_icon_for_user(current_user), alt: current_user.to_reference, class: 'avatar s40'
         .timeline-content.timeline-content-form
           = render "shared/notes/form", view: diff_view, supports_autocomplete: autocomplete
 - elsif !current_user
diff --git a/app/views/shared/projects/_project.html.haml b/app/views/shared/projects/_project.html.haml
index 2a75b46d376..33435216c14 100644
--- a/app/views/shared/projects/_project.html.haml
+++ b/app/views/shared/projects/_project.html.haml
@@ -17,7 +17,7 @@
       .avatar-container.s40
         = link_to project_path(project), class: dom_class(project) do
           - if project.creator && use_creator_avatar
-            = image_tag avatar_icon(project.creator.email, 40), class: "avatar s40", alt:''
+            = image_tag avatar_icon_for_user(project.creator, 40), class: "avatar s40", alt:''
           - else
             = project_icon(project, alt: '', class: 'avatar project-avatar s40')
     .project-details
diff --git a/app/views/shared/snippets/_snippet.html.haml b/app/views/shared/snippets/_snippet.html.haml
index 57b445321e2..491a8a41090 100644
--- a/app/views/shared/snippets/_snippet.html.haml
+++ b/app/views/shared/snippets/_snippet.html.haml
@@ -1,7 +1,7 @@
 - link_project = local_assigns.fetch(:link_project, false)
 
 %li.snippet-row
-  = image_tag avatar_icon(snippet.author), class: "avatar s40 hidden-xs", alt: ''
+  = image_tag avatar_icon_for_user(snippet.author), class: "avatar s40 hidden-xs", alt: ''
 
   .title
     = link_to reliable_snippet_path(snippet) do
diff --git a/app/views/users/show.html.haml b/app/views/users/show.html.haml
index 90aa1be30ac..c9a77d668a2 100644
--- a/app/views/users/show.html.haml
+++ b/app/views/users/show.html.haml
@@ -35,8 +35,8 @@
 
     .profile-header
       .avatar-holder
-        = link_to avatar_icon(@user, 400), target: '_blank', rel: 'noopener noreferrer' do
-          = image_tag avatar_icon(@user, 90), class: "avatar s90", alt: ''
+        = link_to avatar_icon_for_user(@user, 400), target: '_blank', rel: 'noopener noreferrer' do
+          = image_tag avatar_icon_for_user(@user, 90), class: "avatar s90", alt: ''
 
       .user-info
         .cover-title
diff --git a/changelogs/unreleased/42800-change-usage-of-avatar_icon.yml b/changelogs/unreleased/42800-change-usage-of-avatar_icon.yml
new file mode 100644
index 00000000000..00f4b7436a7
--- /dev/null
+++ b/changelogs/unreleased/42800-change-usage-of-avatar_icon.yml
@@ -0,0 +1,6 @@
+---
+title: Use a user object in ApplicationHelper#avatar_icon where possible to avoid
+  N+1 queries.
+merge_request: 42800
+author:
+type: performance
diff --git a/spec/helpers/application_helper_spec.rb b/spec/helpers/application_helper_spec.rb
index f7a4a7afced..43cb0dfe163 100644
--- a/spec/helpers/application_helper_spec.rb
+++ b/spec/helpers/application_helper_spec.rb
@@ -63,13 +63,29 @@ describe ApplicationHelper do
     end
   end
 
-  describe 'avatar_icon' do
+  describe 'avatar_icon_for' do
+    let!(:user) { create(:user, avatar: File.open(uploaded_image_temp_path), email: 'bar@example.com') }
+    let(:email) { 'foo@example.com' }
+    let!(:another_user) { create(:user, avatar: File.open(uploaded_image_temp_path), email: email) }
+
+    it 'prefers the user to retrieve the avatar_url' do
+      expect(helper.avatar_icon_for(user, email).to_s)
+        .to eq(user.avatar.url)
+    end
+
+    it 'falls back to email lookup if no user given' do
+      expect(helper.avatar_icon_for(nil, email).to_s)
+        .to eq(another_user.avatar.url)
+    end
+  end
+
+  describe 'avatar_icon_for_email' do
     let(:user) { create(:user, avatar: File.open(uploaded_image_temp_path)) }
 
     context 'using an email' do
       context 'when there is a matching user' do
         it 'returns a relative URL for the avatar' do
-          expect(helper.avatar_icon(user.email).to_s)
+          expect(helper.avatar_icon_for_email(user.email).to_s)
             .to eq(user.avatar.url)
         end
       end
@@ -78,17 +94,37 @@ describe ApplicationHelper do
         it 'calls gravatar_icon' do
           expect(helper).to receive(:gravatar_icon).with('foo@example.com', 20, 2)
 
-          helper.avatar_icon('foo@example.com', 20, 2)
+          helper.avatar_icon_for_email('foo@example.com', 20, 2)
+        end
+      end
+
+      context 'without an email passed' do
+        it 'calls gravatar_icon' do
+          expect(helper).to receive(:gravatar_icon).with(nil, 20, 2)
+
+          helper.avatar_icon_for_email(nil, 20, 2)
         end
       end
     end
+  end
+
+  describe 'avatar_icon_for_user' do
+    let(:user) { create(:user, avatar: File.open(uploaded_image_temp_path)) }
 
-    describe 'using a user' do
+    context 'with a user object passed' do
       it 'returns a relative URL for the avatar' do
-        expect(helper.avatar_icon(user).to_s)
+        expect(helper.avatar_icon_for_user(user).to_s)
           .to eq(user.avatar.url)
       end
     end
+
+    context 'without a user object passed' do
+      it 'calls gravatar_icon' do
+        expect(helper).to receive(:gravatar_icon).with(nil, 20, 2)
+
+        helper.avatar_icon_for_user(nil, 20, 2)
+      end
+    end
   end
 
   describe 'gravatar_icon' do
diff --git a/spec/helpers/avatars_helper_spec.rb b/spec/helpers/avatars_helper_spec.rb
index f44e7ef6843..04c6d259135 100644
--- a/spec/helpers/avatars_helper_spec.rb
+++ b/spec/helpers/avatars_helper_spec.rb
@@ -29,7 +29,7 @@ describe AvatarsHelper do
       is_expected.to eq tag(
         :img,
         alt: "#{user.name}'s avatar",
-        src: avatar_icon(user, 16),
+        src: avatar_icon_for_user(user, 16),
         data: { container: 'body' },
         class: 'avatar s16 has-tooltip',
         title: user.name
@@ -43,7 +43,7 @@ describe AvatarsHelper do
         is_expected.to eq tag(
           :img,
           alt: "#{user.name}'s avatar",
-          src: avatar_icon(user, 16),
+          src: avatar_icon_for_user(user, 16),
           data: { container: 'body' },
           class: "avatar s16 #{options[:css_class]} has-tooltip",
           title: user.name
@@ -58,7 +58,7 @@ describe AvatarsHelper do
         is_expected.to eq tag(
           :img,
           alt: "#{user.name}'s avatar",
-          src: avatar_icon(user, options[:size]),
+          src: avatar_icon_for_user(user, options[:size]),
           data: { container: 'body' },
           class: "avatar s#{options[:size]} has-tooltip",
           title: user.name
@@ -89,7 +89,7 @@ describe AvatarsHelper do
           :img,
           alt: "#{user.name}'s avatar",
           src: LazyImageTagHelper.placeholder_image,
-          data: { container: 'body', src: avatar_icon(user, 16) },
+          data: { container: 'body', src: avatar_icon_for_user(user, 16) },
           class: "avatar s16 has-tooltip lazy",
           title: user.name
         )
@@ -104,7 +104,7 @@ describe AvatarsHelper do
           is_expected.to eq tag(
             :img,
             alt: "#{user.name}'s avatar",
-            src: avatar_icon(user, 16),
+            src: avatar_icon_for_user(user, 16),
             data: { container: 'body' },
             class: "avatar s16 has-tooltip",
             title: user.name
@@ -119,7 +119,7 @@ describe AvatarsHelper do
           is_expected.to eq tag(
             :img,
             alt: "#{user.name}'s avatar",
-            src: avatar_icon(user, 16),
+            src: avatar_icon_for_user(user, 16),
             class: "avatar s16",
             title: user.name
           )
@@ -137,7 +137,7 @@ describe AvatarsHelper do
           is_expected.to eq tag(
             :img,
             alt: "#{user.name}'s avatar",
-            src: avatar_icon(user, 16),
+            src: avatar_icon_for_user(user, 16),
             data: { container: 'body' },
             class: "avatar s16 has-tooltip",
             title: user.name
@@ -149,7 +149,7 @@ describe AvatarsHelper do
         is_expected.to eq tag(
           :img,
           alt: "#{options[:user_name]}'s avatar",
-          src: avatar_icon(options[:user_email], 16),
+          src: avatar_icon_for_email(options[:user_email], 16),
           data: { container: 'body' },
           class: "avatar s16 has-tooltip",
           title: options[:user_name]
diff --git a/spec/helpers/projects_helper_spec.rb b/spec/helpers/projects_helper_spec.rb
index c0251bf7dc0..b67fee2fcc0 100644
--- a/spec/helpers/projects_helper_spec.rb
+++ b/spec/helpers/projects_helper_spec.rb
@@ -215,7 +215,7 @@ describe ProjectsHelper do
     let(:expected) { double }
 
     before do
-      expect(helper).to receive(:avatar_icon).with(user, 16).and_return(expected)
+      expect(helper).to receive(:avatar_icon_for_user).with(user, 16).and_return(expected)
     end
 
     it 'returns image tag for member avatar' do