Fixes #3717 - Spaces in front of mentions can cause partly content removal.

app/assets/javascripts/app/lib/base/jquery.textmodule.js

@@ -391,14 +391,10 @@
       start = 0
     }
 
-    // for chrome, remove also leading space, add it later - otherwice space will be tropped
-    if (start) {
-      clone.setStart(range.startContainer, start-1)
-      clone.setEnd(range.startContainer, start)
-      var spacerChar = clone.toString()
-      if (spacerChar === ' ') {
-        start = start - 1
-      }
+    // for chrome, check if space is before trigger if so, add it later - otherwise space will be dropped
+    var addSpacer = false
+    if ( $(range.startContainer.parentNode).html().includes(' ' + string) ) {
+      addSpacer = true
     }
     //this.log('CUT FOR', string, "-"+clone.toString()+"-", start, range.startOffset)
     clone.setStart(range.startContainer, start)
@@ -406,10 +402,8 @@
     clone.deleteContents()
 
     // for chrome, insert space again
-    if (start) {
-      if (spacerChar === ' ') {
-        this.paste(' ')
-      }
+    if (addSpacer) {
+      range.pasteHtml(' ')
     }
   }
 

spec/system/examples/text_modules_examples.rb

@@ -89,6 +89,23 @@ RSpec.shared_examples 'text modules' do |path:|
     end
   end
 
+  it 'does not delete parts of the text on multiple mentions (issue #3717)' do
+    visit path
+    within(:active_content) do
+      find('select[name="group_id"]').select('Users')
+      find(:richtext).send_keys('Testing Testy')
+      find(:richtext).send_keys('@@FFFF1')
+      find(:richtext).send_keys(:enter)
+      find(:richtext).send_keys(:enter)
+      find(:richtext).send_keys('Testing Testy ')
+      find(:richtext).send_keys('@@FFFF1')
+      find(:richtext).send_keys(:enter)
+
+      expect(find(:richtext).text).to include('Testing TestyFFFF1 GGGG1')
+      expect(find(:richtext).text).to include('Testing Testy FFFF1 GGGG1')
+    end
+  end
+
   it 'supports group-dependent text modules' do
 
     # give user access to all groups including those created