IDEA-87087 Code formatting corrupts the code

Don't modify c-style comments white space

java/java-impl/src/com/intellij/psi/formatter/java/JavaSpacePropertyProcessor.java

@@ -78,7 +78,10 @@ public class JavaSpacePropertyProcessor extends JavaElementVisitor {
     }
 
     if (myChild2 != null && StdTokenSets.COMMENT_BIT_SET.contains(myChild2.getElementType())) {
-      if (mySettings.KEEP_FIRST_COLUMN_COMMENT) {
+      if (myChild2.getElementType() == JavaTokenType.C_STYLE_COMMENT) {
+        myResult = Spacing.getReadOnlySpacing();
+      }
+      else if (mySettings.KEEP_FIRST_COLUMN_COMMENT) {
         myResult = Spacing
           .createKeepingFirstColumnSpacing(0, Integer.MAX_VALUE, true, mySettings.KEEP_BLANK_LINES_IN_CODE);
       }

java/java-tests/testSrc/com/intellij/psi/formatter/java/JavaFormatterIndentationTest.java

@@ -489,4 +489,18 @@ public class JavaFormatterIndentationTest extends AbstractJavaFormatterTest {
       ")"
     );
   }
+
+  public void testCStyleCommentIsNotMoved() throws Exception {
+    // IDEA-87087
+    doClassTest(
+      "                /*\n" +
+      "                   this is a c-style comment\n" +
+      "                 */\n" +
+      "           // This is a line comment",
+      "            /*\n" +
+      "               this is a c-style comment\n" +
+      "             */\n" +
+      "// This is a line comment"
+    );
+  }
 }