fix(mail-merge): Fix drag and drop for files vs. chips

internal_packages/composer/lib/composer-editor.jsx

@@ -217,6 +217,9 @@ class ComposerEditor extends Component {
     this.refs.contenteditable._onDragOver(event)
   }
 
+  _shouldAcceptDrop(event) {
+    return this.refs.contenteditable._shouldAcceptDrop(event)
+  }
   // Helpers
 
   _scrollToBottom = ()=> {
@@ -302,7 +305,7 @@ class ComposerEditor extends Component {
         className="composer-inner-wrap"
         onDrop={::this._onDrop}
         onDragOver={::this._onDragOver}
-        shouldAcceptDrop={() => true}
+        shouldAcceptDrop={::this._shouldAcceptDrop}
       >
         <Contenteditable
           ref="contenteditable"

internal_packages/composer/stylesheets/composer.less

@@ -38,6 +38,7 @@ body.platform-win32 {
     border: 4px dashed lighten(@gray, 30%);
     text-align: center;
     line-height:2.3em;
+    pointer-events: none;
 
     .centered {
       position: absolute;

src/components/contenteditable/contenteditable.cjsx

@@ -350,6 +350,11 @@ class Contenteditable extends React.Component
   _onDrop: (event) =>
     @dispatchEventToExtensions("onDrop", event)
 
+  _shouldAcceptDrop: (event) =>
+    for extension in [].concat(@props.extensions, @coreExtensions)
+      return true if extension.shouldAcceptDrop?.call(extension, {event})
+    return false
+
   # We must set the `inCompositionEvent` flag in addition to tearing down
   # the selecton listeners. While the composition event is in progress, we
   # want to ignore any input events we get.

src/components/drop-zone.cjsx

@@ -31,6 +31,7 @@ class DropZone extends React.Component
     @_dragCounter += 1
     if @_dragCounter is 1 and @props.onDragStateChange
       @props.onDragStateChange(isDropping: true)
+    e.stopPropagation()
     return
 
   _onDragLeave: (e) =>
@@ -38,6 +39,7 @@ class DropZone extends React.Component
     @_dragCounter -= 1
     if @_dragCounter is 0 and @props.onDragStateChange
       @props.onDragStateChange(isDropping: false)
+    e.stopPropagation()
     return
 
   _onDrop: (e) =>
@@ -46,6 +48,7 @@ class DropZone extends React.Component
       @props.onDragStateChange(isDropping: false)
     @_dragCounter = 0
     @props.onDrop(e)
+    e.stopPropagation()
     return
 
 module.exports = DropZone

src/pro

@@ -1 +1 @@
-Subproject commit ebef587e6eeef3c3e76bb6c25a52b93e08ee9a00
+Subproject commit c9b1972462e7b09b047456bb96a49db0b62443e3