diff --git a/platform/diff-impl/src/com/intellij/diff/tools/fragmented/UnifiedDiffViewer.java b/platform/diff-impl/src/com/intellij/diff/tools/fragmented/UnifiedDiffViewer.java
index ac45fac60a76..7b4a15e98c20 100644
--- a/platform/diff-impl/src/com/intellij/diff/tools/fragmented/UnifiedDiffViewer.java
+++ b/platform/diff-impl/src/com/intellij/diff/tools/fragmented/UnifiedDiffViewer.java
@@ -79,6 +79,9 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
+import java.awt.*;
+import java.awt.geom.Point2D;
+import java.util.List;
 import java.util.*;
 import java.util.function.IntPredicate;
 import java.util.function.IntUnaryOperator;
@@ -1613,6 +1616,7 @@ public class UnifiedDiffViewer extends ListenerDiffViewerBase implements EditorD
   }
 
   private class UnifiedImaginaryEditor extends ImaginaryEditor {
+    private static final Set<String> ourReportedMockMethods = ContainerUtil.newConcurrentSet();
     private static boolean ourDisableImaginaryEditor = false;
 
     private final Side mySide;
@@ -1629,6 +1633,19 @@ public class UnifiedDiffViewer extends ListenerDiffViewerBase implements EditorD
       return new UnsupportedOperationException("Not implemented. UnifiedDiffViewer.UnifiedImaginaryEditor will be disabled.");
     }
 
+    protected void warnMockImplementation(@NotNull String methodName) {
+      if (ourReportedMockMethods.add(methodName)) {
+        String message = "Method is not applicable. Consider using 'editor instanceOf ImaginaryEditor'";
+        if (ApplicationManager.getApplication().isInternal() ||
+            ApplicationManager.getApplication().isUnitTestMode()) {
+          LOG.error(message);
+        }
+        else {
+          LOG.warn(message);
+        }
+      }
+    }
+
     @Override
     public VirtualFile getVirtualFile() {
       return FileDocumentManager.getInstance().getFile(getDocument());
@@ -1705,5 +1722,74 @@ public class UnifiedDiffViewer extends ListenerDiffViewerBase implements EditorD
     public @NotNull FoldingModel getFoldingModel() {
       return new EmptyFoldingModel();
     }
+
+    @Override
+    public boolean hasHeaderComponent() {
+      return false;
+    }
+
+    @Override
+    public @Nullable JComponent getHeaderComponent() {
+      return null;
+    }
+
+    @Override
+    public void setHeaderComponent(@Nullable JComponent header) {
+      warnMockImplementation("setHeaderComponent");
+    }
+
+    @Override
+    public int getLineHeight() {
+      warnMockImplementation("getLineHeight");
+      return myEditor.getLineHeight();
+    }
+
+    @Override
+    public @NotNull LogicalPosition visualToLogicalPosition(@NotNull VisualPosition visiblePos) {
+      warnMockImplementation("visualToLogicalPosition");
+      return new LogicalPosition(0, 0);
+    }
+
+    @Override
+    public @NotNull LogicalPosition xyToLogicalPosition(@NotNull Point p) {
+      warnMockImplementation("xyToLogicalPosition");
+      return new LogicalPosition(0, 0);
+    }
+
+    @Override
+    public @NotNull VisualPosition logicalToVisualPosition(@NotNull LogicalPosition logicalPos) {
+      warnMockImplementation("logicalToVisualPosition");
+      return new VisualPosition(0, 0);
+    }
+
+    @Override
+    public @NotNull VisualPosition xyToVisualPosition(@NotNull Point p) {
+      warnMockImplementation("xyToVisualPosition");
+      return new VisualPosition(0, 0);
+    }
+
+    @Override
+    public @NotNull VisualPosition xyToVisualPosition(@NotNull Point2D p) {
+      warnMockImplementation("xyToVisualPosition");
+      return new VisualPosition(0, 0);
+    }
+
+    @Override
+    public @NotNull Point logicalPositionToXY(@NotNull LogicalPosition pos) {
+      warnMockImplementation("logicalPositionToXY");
+      return new Point(0, 0);
+    }
+
+    @Override
+    public @NotNull Point visualPositionToXY(@NotNull VisualPosition visible) {
+      warnMockImplementation("visualPositionToXY");
+      return new Point(0, 0);
+    }
+
+    @Override
+    public @NotNull Point2D visualPositionToPoint2D(@NotNull VisualPosition pos) {
+      warnMockImplementation("visualPositionToPoint2D");
+      return new Point(0, 0);
+    }
   }
 }
diff --git a/platform/editor-ui-ex/src/com/intellij/openapi/editor/impl/ImaginaryEditor.java b/platform/editor-ui-ex/src/com/intellij/openapi/editor/impl/ImaginaryEditor.java
index 7e9053883acc..1e7e66324574 100644
--- a/platform/editor-ui-ex/src/com/intellij/openapi/editor/impl/ImaginaryEditor.java
+++ b/platform/editor-ui-ex/src/com/intellij/openapi/editor/impl/ImaginaryEditor.java
@@ -132,7 +132,10 @@ public class ImaginaryEditor extends UserDataHolderBase implements Editor {
 
   @Override
   public int logicalPositionToOffset(@NotNull LogicalPosition pos) {
-    throw notImplemented();
+    int line = MathUtil.clamp(pos.line, 0, myDocument.getLineCount());
+    int startOffset = myDocument.getLineStartOffset(line);
+    int endOffset = myDocument.getLineEndOffset(line);
+    return MathUtil.clamp(startOffset + pos.column, startOffset, endOffset);
   }
 
   @Override
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/daemon/impl/ShowAutoImportPass.java b/platform/lang-impl/src/com/intellij/codeInsight/daemon/impl/ShowAutoImportPass.java
index c99c5e415254..dd7dde0d19b6 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/daemon/impl/ShowAutoImportPass.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/daemon/impl/ShowAutoImportPass.java
@@ -20,6 +20,7 @@ import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.editor.ex.MarkupModelEx;
 import com.intellij.openapi.editor.impl.EditorImpl;
+import com.intellij.openapi.editor.impl.ImaginaryEditor;
 import com.intellij.openapi.keymap.KeymapUtil;
 import com.intellij.openapi.progress.ProgressIndicator;
 import com.intellij.openapi.progress.ProgressManager;
@@ -110,7 +111,7 @@ public final class ShowAutoImportPass extends TextEditorHighlightingPass {
 
       int caretOffset = myEditor.getCaretModel().getOffset();
       importUnambiguousImports();
-      if (isImportHintEnabled()) {
+      if (isImportHintEnabled() && !(myEditor instanceof ImaginaryEditor)) {
         List<HighlightInfo> visibleHighlights = getVisibleHighlights(myVisibleRange, myProject, myEditor, hasDirtyTextRange);
         // sort by distance to the caret
         visibleHighlights.sort(Comparator.comparingInt(info -> Math.abs(info.getActualStartOffset() - caretOffset)));