Fix broken commit auto-scrolling (#5972)

Fix a bug introduced in #5928: dragging a commit with auto-scrolling so
that the original commit leaves the viewport, and then dragging back
into the view would snap the original commit back into view.

Labeled as ignore-for-release because it's a regression in a PR that
wasn't released yet.

pkg/gui/controllers/local_commits_controller.go

@@ -191,7 +191,7 @@ func (self *LocalCommitsController) handleCommitDrag(opts gocui.ViewMouseBinding
 
 	self.commitDrag.hasMoved = true
 	if self.updateCommitDragInsertion(opts.Y) {
-		self.c.PostRefreshUpdate(self.context())
+		self.c.PostRefreshUpdateKeepingScrollPosition(self.context())
 	}
 	originY := self.context().GetView().OriginY()
 	self.dragAutoscroller.Update(opts.Y - originY)

pkg/integration/components/test_test.go

@@ -28,6 +28,9 @@ type fakeGuiDriver struct {
 	heldCoordinates     []coordinate
 	movedCoordinates    []coordinate
 	releasedCoordinates []coordinate
+	scrolledCoordinates []coordinate
+	onUIThread          bool
+	onUIThreadCallCount int
 }
 
 var _ integrationTypes.GuiDriver = &fakeGuiDriver{}
@@ -57,13 +60,17 @@ func (self *fakeGuiDriver) MouseRelease(x, y int) {
 }
 
 func (self *fakeGuiDriver) ScrollWheelDown(x, y int) {
+	self.scrolledCoordinates = append(self.scrolledCoordinates, coordinate{x: x, y: y})
 }
 
 func (self *fakeGuiDriver) RefreshInBackground() {
 }
 
 func (self *fakeGuiDriver) OnUIThreadAndWait(f func()) {
+	self.onUIThreadCallCount++
+	self.onUIThread = true
 	f()
+	self.onUIThread = false
 }
 
 func (self *fakeGuiDriver) FocusIn() {
@@ -167,6 +174,42 @@ func TestSuccess(t *testing.T) {
 	assert.Equal(t, "", driver.failureMessage)
 }
 
+func TestViewDriverPointerCoordinates(t *testing.T) {
+	guiDriver := &fakeGuiDriver{}
+	testDriver := NewTestDriver(guiDriver, nil, config.KeybindingConfig{}, 0)
+	view := gocui.NewView("source", 10, 20, 30, 31, gocui.OutputNormal)
+	targetView := gocui.NewView("target", 40, 50, 60, 61, gocui.OutputNormal)
+	viewDriver := &ViewDriver{
+		getView: func() *gocui.View {
+			assert.True(t, guiDriver.onUIThread)
+			return view
+		},
+		t: testDriver,
+	}
+	targetViewDriver := &ViewDriver{
+		getView: func() *gocui.View {
+			assert.True(t, guiDriver.onUIThread)
+			return targetView
+		},
+		t: testDriver,
+	}
+
+	viewDriver.
+		Click(1, 2).
+		FocusInAndClick(3, 4).
+		ClickAndHold(5, 6).
+		MouseMove(7, 8).
+		MouseMoveToBottom(9).
+		MouseMoveToView(targetViewDriver, 10, 11).
+		ScrollWheelDown()
+
+	assert.Equal(t, []coordinate{{12, 23}, {14, 25}}, guiDriver.clickedCoordinates)
+	assert.Equal(t, []coordinate{{16, 27}}, guiDriver.heldCoordinates)
+	assert.Equal(t, []coordinate{{18, 29}, {20, 30}, {51, 62}}, guiDriver.movedCoordinates)
+	assert.Equal(t, []coordinate{{11, 21}}, guiDriver.scrolledCoordinates)
+	assert.Equal(t, 7, guiDriver.onUIThreadCallCount)
+}
+
 func TestFailingFixture(t *testing.T) {
 	test := NewIntegrationTest(NewIntegrationTestArgs{
 		Description: unitTestDescription,

pkg/integration/components/view_driver.go

@@ -517,7 +517,7 @@ func (self *ViewDriver) PressRapidly(keys ...config.Keybinding) *ViewDriver {
 }
 
 func (self *ViewDriver) Click(x, y int) *ViewDriver {
-	offsetX, offsetY, _, _ := self.getView().Dimensions()
+	offsetX, offsetY, _ := self.viewGeometry()
 
 	self.t.click(offsetX+1+x, offsetY+1+y)
 
@@ -525,7 +525,7 @@ func (self *ViewDriver) Click(x, y int) *ViewDriver {
 }
 
 func (self *ViewDriver) FocusInAndClick(x, y int) *ViewDriver {
-	offsetX, offsetY, _, _ := self.getView().Dimensions()
+	offsetX, offsetY, _ := self.viewGeometry()
 
 	self.t.focusInAndClick(offsetX+1+x, offsetY+1+y)
 
@@ -533,7 +533,7 @@ func (self *ViewDriver) FocusInAndClick(x, y int) *ViewDriver {
 }
 
 func (self *ViewDriver) MouseMoveToView(target *ViewDriver, x, y int) *ViewDriver {
-	offsetX, offsetY, _, _ := target.getView().Dimensions()
+	offsetX, offsetY, _ := target.viewGeometry()
 	self.t.mouseMove(offsetX+1+x, offsetY+1+y)
 	return self
 }
@@ -543,30 +543,42 @@ func (self *ViewDriver) Drag(fromX, fromY, toX, toY int) *ViewDriver {
 }
 
 func (self *ViewDriver) ClickAndHold(x, y int) *ViewDriver {
-	offsetX, offsetY, _, _ := self.getView().Dimensions()
+	offsetX, offsetY, _ := self.viewGeometry()
 	self.t.clickAndHold(offsetX+1+x, offsetY+1+y)
 	return self
 }
 
 func (self *ViewDriver) MouseMove(x, y int) *ViewDriver {
-	offsetX, offsetY, _, _ := self.getView().Dimensions()
+	offsetX, offsetY, _ := self.viewGeometry()
 	self.t.mouseMove(offsetX+1+x, offsetY+1+y)
 	return self
 }
 
 func (self *ViewDriver) MouseMoveToBottom(x int) *ViewDriver {
-	return self.MouseMove(x, self.getView().InnerHeight()-1)
+	offsetX, offsetY, innerHeight := self.viewGeometry()
+	self.t.mouseMove(offsetX+1+x, offsetY+innerHeight)
+	return self
 }
 
 // scrolls the view down by one notch of the mouse wheel, i.e. by
 // gui.scrollHeight lines. This moves the scroll position without moving the
 // selection.
 func (self *ViewDriver) ScrollWheelDown() *ViewDriver {
-	offsetX, offsetY, _, _ := self.getView().Dimensions()
+	offsetX, offsetY, _ := self.viewGeometry()
 	self.t.scrollWheelDown(offsetX+1, offsetY+1)
 	return self
 }
 
+func (self *ViewDriver) viewGeometry() (offsetX int, offsetY int, innerHeight int) {
+	self.t.gui.OnUIThreadAndWait(func() {
+		view := self.getView()
+		offsetX, offsetY, _, _ = view.Dimensions()
+		innerHeight = view.InnerHeight()
+	})
+
+	return offsetX, offsetY, innerHeight
+}
+
 func (self *ViewDriver) RepeatMouseMove() *ViewDriver {
 	self.t.repeatMouseMove()
 	return self

pkg/integration/tests/interactive_rebase/drag_to_reorder_with_autoscroll.go

@@ -19,14 +19,22 @@ var DragToReorderWithAutoscroll = NewIntegrationTest(NewIntegrationTestArgs{
 			TopLines(
 				Contains("commit-40").IsSelected(),
 			).
+			// Click and hold the first commit
 			ClickAndHold(1, 0).
+			// Move the mouse to the bottom of the panel to trigger autoscroll
 			MouseMoveToBottom(1).
+			// Verify that the view scrolls
+			OriginYAtLeast(3).
+			// Move the mouse back into the viewport
+			MouseMove(1, 1).
+			// This keeps the scroll as it was
 			OriginYAtLeast(3).
 			MouseRelease().
 			SelectedLines(
 				Contains("commit-40"),
 			).
 			SelectedLineIdxAtLeast(3).
+			// Scroll back to verify that the original commit is no longer at the top
 			GotoTop().
 			TopLines(
 				Contains("commit-39").IsSelected(),