fix NPE in KDocLinkParser

compiler/frontend/src/org/jetbrains/kotlin/kdoc/parser/KDocLinkParser.kt

@@ -92,5 +92,5 @@ class KDocLinkParser(): PsiParser {
         }
     }
 
-    private fun isName(tokenType: IElementType) = tokenType == JetTokens.IDENTIFIER || tokenType in JetTokens.KEYWORDS
+    private fun isName(tokenType: IElementType?) = tokenType == JetTokens.IDENTIFIER || tokenType in JetTokens.KEYWORDS
 }

compiler/testData/psi/kdoc/SeeEmpty.kt

@@ -0,0 +1,4 @@
+/**
+ * @see
+ * @see A.
+ */

compiler/testData/psi/kdoc/SeeEmpty.txt

@@ -0,0 +1,25 @@
+JetFile: SeeEmpty.kt
+  PACKAGE_DIRECTIVE
+    <empty list>
+  KDoc
+    PsiElement(KDOC_START)('/**')
+    PsiWhiteSpace('\n ')
+    KDOC_SECTION
+      PsiElement(KDOC_LEADING_ASTERISK)('*')
+      PsiElement(KDOC_TEXT)(' ')
+      KDOC_TAG
+        PsiElement(KDOC_TAG_NAME)('@see')
+      PsiWhiteSpace('\n ')
+      PsiElement(KDOC_LEADING_ASTERISK)('*')
+      PsiElement(KDOC_TEXT)(' ')
+      KDOC_TAG
+        PsiElement(KDOC_TAG_NAME)('@see')
+        PsiWhiteSpace(' ')
+        KDOC_MARKDOWN_LINK
+          KDOC_NAME
+            PsiElement(IDENTIFIER)('A')
+          PsiElement(DOT)('.')
+          PsiErrorElement:Identifier expected
+            <empty list>
+    PsiWhiteSpace('\n ')
+    PsiElement(KDOC_END)('*/')

compiler/tests/org/jetbrains/kotlin/parsing/JetParsingTestGenerated.java

@@ -1127,6 +1127,12 @@ public class JetParsingTestGenerated extends AbstractJetParsingTest {
                 doParsingTest(fileName);
             }
 
+            @TestMetadata("SeeEmpty.kt")
+            public void testSeeEmpty() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/psi/kdoc/SeeEmpty.kt");
+                doParsingTest(fileName);
+            }
+
             @TestMetadata("SeeLink.kt")
             public void testSeeLink() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/psi/kdoc/SeeLink.kt");