Minor fixes for incsearch highlighting and caret/scroll position for undo

src/main/java/com/maddyhome/idea/vim/helper/SearchHighlightsHelper.kt

@@ -102,7 +102,8 @@ private fun updateSearchHighlights(
   // Update highlights in all visible editors. We update non-visible editors when they get focus.
   // Note that this now includes all editors - main, diff windows, even toolwindows like the Commit editor and consoles
   val editors = injector.editorGroup.getEditors().filter {
-    injector.application.isUnitTest() || it.ij.component.isShowing
+    (injector.application.isUnitTest() || it.ij.component.isShowing)
+      && (currentEditor == null || it.projectId == currentEditor.projectId)
   }
 
   editors.forEach {

src/main/java/com/maddyhome/idea/vim/helper/UndoRedoHelper.kt

@@ -14,7 +14,9 @@ import com.intellij.openapi.command.CommandProcessor
 import com.intellij.openapi.command.undo.UndoManager
 import com.intellij.openapi.components.Service
 import com.intellij.openapi.diagnostic.logger
+import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.fileEditor.TextEditor
+import com.intellij.openapi.fileEditor.TextEditorWithPreview
 import com.intellij.openapi.fileEditor.impl.text.TextEditorProvider
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.registry.Registry
@@ -42,13 +44,13 @@ internal class UndoRedoHelper : UndoRedoBase() {
   override fun undo(editor: VimEditor, context: ExecutionContext): Boolean {
     val ijContext = context.context as DataContext
     val project = PlatformDataKeys.PROJECT.getData(ijContext) ?: return false
-    val fileEditor = TextEditorProvider.getInstance().getTextEditor(editor.ij)
+    val textEditor = getTextEditor(editor.ij)
     val undoManager = UndoManager.getInstance(project)
-    if (undoManager.isUndoAvailable(fileEditor)) {
+    if (undoManager.isUndoAvailable(textEditor)) {
       val scrollingModel = editor.getScrollingModel()
       scrollingModel.accumulateViewportChanges()
 
-      performUndo(editor, undoManager, fileEditor)
+      performUndo(editor, undoManager, textEditor)
 
       scrollingModel.flushViewportChanges()
 
@@ -57,6 +59,15 @@ internal class UndoRedoHelper : UndoRedoBase() {
     return false
   }
 
+  private fun getTextEditor(editor: Editor): TextEditor {
+    // If the Editor is hosted in a TextEditor with a preview, then TextEditorProvider will return a TextEditor for the
+    // hosted instance, not for the main editor that also contains the preview. If we pass the inner TextEditor to the
+    // UndoManager, it doesn't correctly restore state. Specifically, the change is undone/redone, but the caret is not
+    // moved. See VIM-3671.
+    val currentTextEditor = TextEditorProvider.getInstance().getTextEditor(editor)
+    return TextEditorWithPreview.getParentSplitEditor(currentTextEditor) as? TextEditor ?: currentTextEditor
+  }
+
   private fun performUndo(
     editor: VimEditor,
     undoManager: UndoManager,
@@ -112,10 +123,10 @@ internal class UndoRedoHelper : UndoRedoBase() {
   override fun redo(editor: VimEditor, context: ExecutionContext): Boolean {
     val ijContext = context.context as DataContext
     val project = PlatformDataKeys.PROJECT.getData(ijContext) ?: return false
-    val fileEditor = TextEditorProvider.getInstance().getTextEditor(editor.ij)
+    val textEditor = getTextEditor(editor.ij)
     val undoManager = UndoManager.getInstance(project)
-    if (undoManager.isRedoAvailable(fileEditor)) {
-      performRedo(undoManager, fileEditor, editor)
+    if (undoManager.isRedoAvailable(textEditor)) {
+      performRedo(undoManager, textEditor, editor)
 
       return true
     }

src/test/java/org/jetbrains/plugins/ideavim/action/change/UndoActionTest.kt

@@ -162,6 +162,16 @@ class UndoActionTest : VimTestCase() {
     configureByText("Lorem ${c}ipsum dolor sit amet")
   }
 
+  @Test
+  @TestFor(issues = ["VIM-3671"])
+  fun `test undo scrolls caret to reset scrolloff`() {
+    configureByLines(200, "lorem ipsum dolor sit amet")
+    enterCommand("set scrolloff=10")
+    typeText("50G", "dd", "G", "u")
+    assertPosition(49, 0)
+    assertVisibleArea(39, 73)
+  }
+
   private fun hasSelection(): Boolean {
     val editor = fixture.editor
     return editor.caretModel.primaryCaret.hasSelection()

src/test/java/org/jetbrains/plugins/ideavim/ex/implementation/commands/RedoCommandTest.kt

@@ -8,6 +8,7 @@
 
 package org.jetbrains.plugins.ideavim.ex.implementation.commands
 
+import com.intellij.idea.TestFor
 import com.maddyhome.idea.vim.api.injector
 import com.maddyhome.idea.vim.vimscript.model.commands.RedoCommand
 import org.jetbrains.plugins.ideavim.VimTestCase
@@ -20,4 +21,15 @@ class RedoCommandTest : VimTestCase() {
     val command = injector.vimscriptParser.parseCommand("redo")
     assertTrue(command is RedoCommand)
   }
-}
+
+  @Test
+  @TestFor(issues = ["VIM-3671"])
+  fun `test redo scrolls caret to reset scrolloff`() {
+    configureByLines(200, "lorem ipsum dolor sit amet")
+    enterCommand("set scrolloff=10")
+    typeText("50G", "dd", "u", "G")
+    enterCommand("redo")
+    assertPosition(49, 0)
+    assertVisibleArea(39, 73)
+  }
+}

src/test/java/org/jetbrains/plugins/ideavim/ex/implementation/commands/UndoCommandTest.kt

@@ -8,6 +8,7 @@
 
 package org.jetbrains.plugins.ideavim.ex.implementation.commands
 
+import com.intellij.idea.TestFor
 import com.maddyhome.idea.vim.api.injector
 import com.maddyhome.idea.vim.vimscript.model.commands.UndoCommand
 import org.jetbrains.plugins.ideavim.VimTestCase
@@ -20,4 +21,15 @@ class UndoCommandTest : VimTestCase() {
     val command = injector.vimscriptParser.parseCommand("undo")
     assertTrue(command is UndoCommand)
   }
-}
+
+  @Test
+  @TestFor(issues = ["VIM-3671"])
+  fun `test undo scrolls caret to reset scrolloff`() {
+    configureByLines(200, "lorem ipsum dolor sit amet")
+    enterCommand("set scrolloff=10")
+    typeText("50G", "dd", "G")
+    enterCommand("undo")
+    assertPosition(49, 0)
+    assertVisibleArea(39, 73)
+  }
+}

vim-engine/src/main/kotlin/com/maddyhome/idea/vim/action/change/RedoAction.kt

@@ -31,6 +31,7 @@ class RedoAction : VimActionHandler.SingleExecution() {
     while ((--count > 0) && result) {
       result = injector.undo.redo(editor, context)
     }
+    injector.scroll.scrollCaretIntoView(editor)
     return result
   }
 }

vim-engine/src/main/kotlin/com/maddyhome/idea/vim/action/change/UndoAction.kt

@@ -31,6 +31,7 @@ class UndoAction : VimActionHandler.SingleExecution() {
     while ((--count > 0) && result) {
       result = injector.undo.undo(editor, context)
     }
+    injector.scroll.scrollCaretIntoView(editor)
     return result
   }
 }

vim-engine/src/main/kotlin/com/maddyhome/idea/vim/vimscript/model/commands/RedoCommand.kt

@@ -23,6 +23,9 @@ import com.maddyhome.idea.vim.vimscript.model.ExecutionResult
 data class RedoCommand(val range: Range, val argument: String) : Command.SingleExecution(range, argument) {
   override val argFlags: CommandHandlerFlags = flags(RangeFlag.RANGE_FORBIDDEN, ArgumentFlag.ARGUMENT_FORBIDDEN, Access.WRITABLE)
   override fun processCommand(editor: VimEditor, context: ExecutionContext, operatorArguments: OperatorArguments): ExecutionResult {
-    return if (injector.undo.redo(editor, context)) ExecutionResult.Success else ExecutionResult.Error
+    return if (injector.undo.redo(editor, context)) {
+      injector.scroll.scrollCaretIntoView(editor)
+      ExecutionResult.Success
+    } else ExecutionResult.Error
   }
 }

vim-engine/src/main/kotlin/com/maddyhome/idea/vim/vimscript/model/commands/UndoCommand.kt

@@ -24,6 +24,9 @@ data class UndoCommand(val range: Range, val argument: String) : Command.SingleE
   override val argFlags: CommandHandlerFlags = flags(RangeFlag.RANGE_FORBIDDEN, ArgumentFlag.ARGUMENT_FORBIDDEN, Access.WRITABLE)
 
   override fun processCommand(editor: VimEditor, context: ExecutionContext, operatorArguments: OperatorArguments): ExecutionResult {
-    return if (injector.undo.undo(editor, context)) ExecutionResult.Success else ExecutionResult.Error
+    return if (injector.undo.undo(editor, context)) {
+      injector.scroll.scrollCaretIntoView(editor)
+      ExecutionResult.Success
+    } else ExecutionResult.Error
   }
 }