Copy as GFM even when parts of other elements are selected

app/assets/javascripts/copy_as_gfm.js

@@ -330,10 +330,26 @@ class CopyAsGFM {
   }
 
   static transformGFMSelection(documentFragment) {
-    // If the documentFragment contains more than just Markdown, don't copy as GFM.
-    if (documentFragment.querySelector('.md, .wiki')) return null;
+    const gfmEls = documentFragment.querySelectorAll('.md, .wiki');
+    switch (gfmEls.length) {
+      case 0: {
+        return documentFragment;
+      }
+      case 1: {
+        return gfmEls[0];
+      }
+      default: {
+        const allGfmEl = document.createElement('div');
+
+        for (let i = 0; i < gfmEls.length; i += 1) {
+          const lineEl = gfmEls[i];
+          allGfmEl.appendChild(lineEl);
+          allGfmEl.appendChild(document.createTextNode('\n\n'));
+        }
 
-    return documentFragment;
+        return allGfmEl;
+      }
+    }
   }
 
   static transformCodeSelection(documentFragment) {

app/assets/javascripts/shortcuts_issuable.js

@@ -38,7 +38,7 @@ import './shortcuts_navigation';
     }
 
     ShortcutsIssuable.prototype.replyWithSelectedText = function() {
-      var quote, documentFragment, selected, separator;
+      var quote, documentFragment, el, selected, separator;
       var replyField = $('.js-main-target-form #note_note');
 
       documentFragment = window.gl.utils.getSelectedFragment();
@@ -47,10 +47,8 @@ import './shortcuts_navigation';
         return;
       }
 
-      // If the documentFragment contains more than just Markdown, don't copy as GFM.
-      if (documentFragment.querySelector('.md, .wiki')) return;
-
-      selected = window.gl.CopyAsGFM.nodeToGFM(documentFragment);
+      el = window.gl.CopyAsGFM.transformGFMSelection(documentFragment.cloneNode(true));
+      selected = window.gl.CopyAsGFM.nodeToGFM(el);
 
       if (selected.trim() === "") {
         return;

changelogs/unreleased/dm-copy-gfm-when-parts-of-other-elements-are-selected.yml

+---
+title: Copy as GFM even when parts of other elements are selected
+merge_request:
+author: