fixed PY-6410 Adding/Pasting text at the end of a class method causes the next class method to be moved outside the class

python/src/META-INF/python-plugin-common.xml

@@ -4,6 +4,7 @@
   <resource-bundle>com.jetbrains.python.PyBundle</resource-bundle>
 
   <extensions defaultExtensionNs="com.intellij">
+    <copyPastePreProcessor implementation="com.jetbrains.python.editor.PythonCopyPasteProcessor"/>
     <errorHandler implementation="com.intellij.diagnostic.ITNReporter"/>
     <fileTypeFactory implementation="com.jetbrains.python.PythonFileTypeFactory"/>
     <fileTypeDetector implementation="com.jetbrains.python.PyFileTypeDetector"/>

python/src/com/jetbrains/python/editor/PythonCopyPasteProcessor.java

@@ -0,0 +1,52 @@
+package com.jetbrains.python.editor;
+
+import com.intellij.codeInsight.editorActions.CopyPastePreProcessor;
+import com.intellij.openapi.editor.CaretModel;
+import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.editor.RawText;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.text.StringUtil;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.PsiWhiteSpace;
+import com.intellij.psi.util.PsiUtilCore;
+
+/**
+ * User : catherine
+ */
+public class PythonCopyPasteProcessor implements CopyPastePreProcessor {
+
+  @Override
+  public String preprocessOnCopy(PsiFile file, int[] startOffsets, int[] endOffsets, String text) {
+    return null;
+  }
+
+  @Override
+  public String preprocessOnPaste(Project project,
+                                  PsiFile file,
+                                  Editor editor,
+                                  String text,
+                                  RawText rawText) {
+    final CaretModel caretModel = editor.getCaretModel();
+    final Document document = editor.getDocument();
+
+    if (StringUtil.startsWithWhitespace(text) && StringUtil.endsWithLineBreak(text)) {
+      final int caretOffset = caretModel.getOffset();
+      final PsiElement element = PsiUtilCore.getElementAtOffset(file, caretOffset-1);
+      final int lineNumber = document.getLineNumber(caretOffset);
+      final int offset = getLineStartSafeOffset(document, lineNumber);
+      final PsiElement element1 = PsiUtilCore.getElementAtOffset(file, offset);
+      if (element instanceof PsiWhiteSpace && element == element1) {
+        caretModel.moveToOffset(offset);
+      }
+    }
+    return text;
+  }
+
+  public int getLineStartSafeOffset(final Document document, int line) {
+    if (line == document.getLineCount()) return document.getTextLength();
+    return document.getLineStartOffset(line);
+  }
+
+}

python/testData/copyPaste/Indent3.after.py

@@ -0,0 +1,3 @@
+class A:
+    a = 1
+    b = 2

python/testData/copyPaste/Indent3.dst.py

@@ -0,0 +1,2 @@
+class A:
+ <caret>   b = 2

python/testData/copyPaste/Indent3.src.py

@@ -0,0 +1,3 @@
+class C:
+<selection>    a = 1
+</selection>

python/testSrc/com/jetbrains/python/PyCopyPasteTest.java

@@ -32,6 +32,10 @@ public class PyCopyPasteTest extends PyTestCase {
     doTest();
   }
 
+  public void testIndent3() {
+    doTest();
+  }
+
   public void testIndentIncrease() {
     doTest();
   }