Support spec.keepAdjacent in joinForwards and joinBackwards

Author: tslocke

src/commands.js

@@ -36,7 +36,7 @@ export function joinBackward(state, dispatch, view) {
 
   let before = $cut.nodeBefore
   // Apply the joining algorithm
-  if (!before.type.spec.isolating && deleteBarrier(state, $cut, dispatch))
+  if (!before.type.spec.isolating && !before.type.spec.keepAdjacent && deleteBarrier(state, $cut, dispatch))
     return true
 
   // If the node below has no content and the node above is
@@ -118,7 +118,7 @@ export function joinForward(state, dispatch, view) {
 
   let after = $cut.nodeAfter
   // Try the joining algorithm
-  if (deleteBarrier(state, $cut, dispatch)) return true
+  if (!after.type.spec.keepAdjacent && deleteBarrier(state, $cut, dispatch)) return true
 
   // If the node above has no content and the node below is
   // selectable, delete the node above and select the one below.