Improved preview detection for attachment.

app/assets/javascripts/app/controllers/ticket_zoom/article_image_view.coffee

@@ -12,7 +12,7 @@ class App.TicketZoomArticleImageView extends App.ControllerModal
     'click .js-close':  'cancel'
 
   content: ->
-    "<div class=\"centered\">#{@image}</div>"
+    "<div class=\"centered imagePreview\">#{@image}</div>"
 
   onSubmit: =>
     url = "#{$(@image).attr('src')}?disposition=attachment"

app/assets/javascripts/app/index.coffee

@@ -137,6 +137,7 @@ class App extends Spine.Controller
       App.i18n.translateContent(string)
 
     ContentTypeIcon: (contentType) ->
+      contentType = App.Utils.contentTypeCleanup(contentType)
       icons =
         # image
         'image/jpeg': 'file-image'
@@ -172,6 +173,7 @@ class App extends Spine.Controller
       return icons[contentType]
 
     canDownload: (contentType) ->
+      contentType = App.Utils.contentTypeCleanup(contentType)
       contentType != 'text/html'
 
     canPreview: (contentType) ->

app/assets/javascripts/app/lib/app_post/utils.coffee

@@ -913,6 +913,11 @@ class App.Utils
             result.push localResult[0]
     result
 
+  @contentTypeCleanup: (contentType) ->
+    return contentType if !contentType
+    contentType = contentType.replace(/^(.+?\/.+?)(\b|\s).+?$/, '$1')
+    contentType
+
   @getRecipientArticle: (ticket, article, article_created_by, type, email_addresses = [], all) ->
 
     # empty form

app/assets/stylesheets/zammad.scss

@@ -7206,6 +7206,11 @@ label + .wizard-buttonList {
   opacity: 0;
 }
 
+.imagePreview img {
+  max-width: 100%;
+  max-height: 100%;
+}
+
 .imageCropper p {
   margin: 0;
 }

public/assets/tests/html_utils.js

@@ -2606,3 +2606,41 @@ test('check getRecipientArticle format', function() {
 });
 
 }
+
+test("contentTypeCleanup", function() {
+
+  var source = "image/png"
+  var should = "image/png"
+  var result = App.Utils.contentTypeCleanup(source)
+  equal(result, should, source)
+
+  source = "image/png; some.file"
+  should = "image/png"
+  result = App.Utils.contentTypeCleanup(source)
+  equal(result, should, source)
+
+  source = "image/png;some.file"
+  should = "image/png"
+  result = App.Utils.contentTypeCleanup(source)
+  equal(result, should, source)
+
+  source = "image/jpeg;some.file"
+  should = "image/jpeg"
+  result = App.Utils.contentTypeCleanup(source)
+  equal(result, should, source)
+
+  source = "image/jpg;some.file"
+  should = "image/jpg"
+  result = App.Utils.contentTypeCleanup(source)
+  equal(result, should, source)
+
+  source = "image/gif;some.file"
+  should = "image/gif"
+  result = App.Utils.contentTypeCleanup(source)
+  equal(result, should, source)
+
+  source = "image/gif\n;some.file"
+  should = "image/gif"
+  result = App.Utils.contentTypeCleanup(source)
+  equal(result, should, source)
+});