Ensure read-only text editors are not considered 'modified'. Also clear read-only flag on successful save.

spec/text-editor-spec.js

@@ -85,6 +85,23 @@ describe('TextEditor', () => {
     })
   })
 
+  describe('when the editor is readonly', () => {
+    it('overrides TextBuffer.isModified to return false', async () => {
+      const editor = await atom.workspace.open(null, {readOnly: true})
+      editor.setText('I am altering the buffer, pray I do not alter it any further')
+      expect(editor.isModified()).toBe(false)
+      editor.setReadOnly(false)
+      expect(editor.isModified()).toBe(true)
+    })
+    it('clears the readonly status when saved', async () => {
+      const editor = await atom.workspace.open(null, {readOnly: true})
+      editor.setText('I am altering the buffer, pray I do not alter it any further')
+      expect(editor.isReadOnly()).toBe(true)
+      await editor.saveAs(temp.openSync('was-readonly').path)
+      expect(editor.isReadOnly()).toBe(false)
+    })
+  })
+
   describe('when the editor is constructed with the largeFileMode option set to true', () => {
     it("loads the editor but doesn't tokenize", async () => {
       editor = await atom.workspace.openTextFile('sample.js', {largeFileMode: true})

src/text-editor.js

@@ -411,6 +411,7 @@ class TextEditor {
             if (this.component != null) {
               this.component.scheduleUpdate()
             }
+            this.buffer.emitModifiedStatusChanged(this.isModified())
           }
           break
 
@@ -575,6 +576,11 @@ class TextEditor {
     this.disposables.add(this.buffer.onDidChangeModified(() => {
       if (!this.hasTerminatedPendingState && this.buffer.isModified()) this.terminatePendingState()
     }))
+    this.disposables.add(this.buffer.onDidSave(() => {
+      if (this.isReadOnly()) {
+        this.setReadOnly(false)
+      }
+    }))
   }
 
   terminatePendingState () {
@@ -1126,7 +1132,7 @@ class TextEditor {
   setEncoding (encoding) { this.buffer.setEncoding(encoding) }
 
   // Essential: Returns {Boolean} `true` if this editor has been modified.
-  isModified () { return this.buffer.isModified() }
+  isModified () { return this.isReadOnly() ? false : this.buffer.isModified() }
 
   // Essential: Returns {Boolean} `true` if this editor has no content.
   isEmpty () { return this.buffer.isEmpty() }