Collapsed comments containing * get removed in the summary line (KT-21994)

#KT-21994 Fixed

idea/src/org/jetbrains/kotlin/idea/KotlinFoldingBuilder.kt

@@ -37,8 +37,10 @@ import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
 
 class KotlinFoldingBuilder : CustomFoldingBuilder(), DumbAware {
-    override fun buildLanguageFoldRegions(descriptors: MutableList<FoldingDescriptor>,
+    override fun buildLanguageFoldRegions(
-                                          root: PsiElement, document: Document, quick: Boolean) {
+        descriptors: MutableList<FoldingDescriptor>,
+        root: PsiElement, document: Document, quick: Boolean
+    ) {
         if (root !is KtFile) {
             return
         }
@@ -126,10 +128,10 @@ class KotlinFoldingBuilder : CustomFoldingBuilder(), DumbAware {
 
     private fun getCommentContents(line: String): String {
         return line.trim()
-                .replace("/**", "")
+            .removePrefix("/**")
-                .replace("/*", "")
+            .removePrefix("/*")
-                .replace("*/", "")
+            .removePrefix("*/")
-                .replace("*", "")
+            .removePrefix("*")
             .trim()
     }
 
@@ -150,8 +152,7 @@ class KotlinFoldingBuilder : CustomFoldingBuilder(), DumbAware {
         return false
     }
 
-    override fun isCustomFoldingRoot(node: ASTNode)
+    override fun isCustomFoldingRoot(node: ASTNode) = node.elementType == KtNodeTypes.BLOCK || node.elementType == KtNodeTypes.CLASS_BODY
-        = node.elementType == KtNodeTypes.BLOCK || node.elementType == KtNodeTypes.CLASS_BODY
 
     private fun isFirstElementInFile(element: PsiElement): Boolean {
         val parent = element.parent

idea/testData/folding/checkCollapse/headerKDoc.kt

@@ -3,8 +3,8 @@
  */</fold>
 package some
 
-<fold text='/** Other ...*/' expand='true'>/**
+<fold text='/** Other 1 * 2 ...*/' expand='true'>/**
- * Other
+ * Other 1 * 2
  */</fold>
 
 // SET_TRUE: setCollapseFileHeader