[by: nicity] IDEA-77340 Incorrect indentation on pasting a method with empty line before (in Indent Block mode)

1. Doc comment is added;
2. Test is added;

java/java-tests/testSrc/com/intellij/codeInsight/editorActions/BlockIndentOnPasteTest.groovy

@@ -580,7 +580,44 @@ class Test {
 '''
     doTest(before, toPaste2, expected2)
   }
-
+  
+  void testPasteMultilineTextThatStartsWithLineFeedToNewLineWithBigCaretIndent() {
+      def before = '''\
+  class Test {
+      void test(int i) {
+          if (i > 0) {
+                   <caret>
+          }
+      }
+  }\
+'''
+  
+      def toPaste = '''
+                       test(1);
+                       test(1);\
+'''
+  
+      def expected = '''\
+  class Test {
+      void test(int i) {
+          if (i > 0) {
+                   
+              test(1);
+              test(1);
+          }
+      }
+  }\
+'''
+      doTest(before, toPaste, expected)
+    
+    
+    def toPaste2 = '''
+     test(1);
+     test(1);\
+'''
+    doTest(before, toPaste2, expected)
+  } 
+  
   def testPlainTextPaste() {
     def before = '''\
   line1

platform/lang-impl/src/com/intellij/codeInsight/editorActions/PasteHandler.java

@@ -519,7 +519,19 @@ public class PasteHandler extends EditorActionHandler implements EditorTextInser
       }
       return;
     }
-
+    
+    // We've pasted text to the non-first column and exact white space between the line start and caret position on the moment of paste
+    // has been removed by formatter during 'adjust line indent'
+    // Example:
+    //       copied text:
+    //                 '   line1
+    //                       line2'
+    //       after paste:
+    //          line start -> '   I   line1
+    //                              line2' (I - caret position during 'paste')
+    //       formatter removed white space between the line start and caret position, so, current document state is:
+    //                        '   line1
+    //                              line2'
     if (anchorLine == firstLine && -diff == startOffset - firstLineStart) {
       return;
     }