Add setting to disable middle mouse paste (atom#21864)

* Add editor setting

* Only paste on middle click if selectionClipboard is true

* Add specs

spec/text-editor-component-spec.js

@@ -4051,6 +4051,7 @@ describe('TextEditorComponent', () => {
     describe('on the lines', () => {
       describe('when there is only one cursor', () => {
         it('positions the cursor on single-click or when middle-clicking', async () => {
+          atom.config.set('editor.selectionClipboard', true);
           for (const button of [0, 1]) {
             const { component, editor } = buildComponent();
             const { lineHeight } = component.measurements;
@@ -4798,6 +4799,7 @@ describe('TextEditorComponent', () => {
         const { component, editor } = buildComponent({ platform: 'linux' });
 
         // Middle mouse pasting.
+        atom.config.set('editor.selectionClipboard', true);
         editor.setSelectedBufferRange([[1, 6], [1, 10]]);
         await conditionPromise(() => TextEditor.clipboard.read() === 'sort');
         component.didMouseDownOnContent({
@@ -4809,7 +4811,19 @@ describe('TextEditorComponent', () => {
         expect(editor.lineTextForBufferRow(10)).toBe('sort');
         editor.undo();
 
+        // Doesn't paste when middle mouse button is clicked
+        atom.config.set('editor.selectionClipboard', false);
+        editor.setSelectedBufferRange([[1, 6], [1, 10]]);
+        component.didMouseDownOnContent({
+          button: 1,
+          clientX: clientLeftForCharacter(component, 10, 0),
+          clientY: clientTopForLine(component, 10)
+        });
+        expect(TextEditor.clipboard.read()).toBe('sort');
+        expect(editor.lineTextForBufferRow(10)).toBe('');
+
         // Ensure left clicks don't interfere.
+        atom.config.set('editor.selectionClipboard', true);
         editor.setSelectedBufferRange([[1, 2], [1, 5]]);
         await conditionPromise(() => TextEditor.clipboard.read() === 'var');
         component.didMouseDownOnContent({

src/config-schema.js

@@ -660,4 +660,12 @@ if (process.platform === 'darwin') {
   };
 }
 
+if (process.platform === 'linux') {
+  configSchema.editor.properties.selectionClipboard = {
+    type: 'boolean',
+    default: true,
+    description: 'Enable pasting on middle mouse button click'
+  };
+}
+
 module.exports = configSchema;

src/text-editor-component.js

@@ -1969,8 +1969,12 @@ module.exports = class TextEditorComponent {
 
       // On Linux, pasting happens on middle click. A textInput event with the
       // contents of the selection clipboard will be dispatched by the browser
-      // automatically on mouseup.
-      if (platform === 'linux' && this.isInputEnabled())
+      // automatically on mouseup if editor.selectionClipboard is set to true.
+      if (
+        platform === 'linux' &&
+        this.isInputEnabled() &&
+        atom.config.get('editor.selectionClipboard')
+      )
         model.insertText(clipboard.readText('selection'));
       return;
     }