[java] fixes broken generic signature parsing (IDEA-158330)

java/java-psi-impl/src/com/intellij/psi/impl/compiled/SignatureParsing.java

@@ -98,15 +98,18 @@ public class SignatureParsing {
     }
   }
 
-  private static String parseTypeVariableRefSignature(CharacterIterator signature) {
+  private static String parseTypeVariableRefSignature(CharacterIterator signature) throws ClsFormatException {
     StringBuilder id = new StringBuilder();
 
     signature.next();
-    while (signature.current() != ';' && signature.current() != '>') {
+    while (signature.current() != ';' && signature.current() != '>' && signature.current() != CharacterIterator.DONE) {
       id.append(signature.current());
       signature.next();
     }
 
+    if (signature.current() == CharacterIterator.DONE) {
+      throw new ClsFormatException();
+    }
     if (signature.current() == ';') {
       signature.next();
     }

java/java-tests/testSrc/com/intellij/psi/SignatureParsingTest.java

@@ -41,6 +41,11 @@ public class SignatureParsingTest {
     assertEquals("p.Obj$.I<p.$Obj1.I,p.Obj2.I$>", parseTypeString("Lp/Obj$$I<Lp/$Obj1$I;Lp/Obj2$I$;>;"));
   }
 
+  @Test(expected = ClsFormatException.class)
+  public void testIllegal() throws ClsFormatException {
+    parseTypeString("T");
+  }
+
   private static String parseTypeString(String signature) throws ClsFormatException {
     return SignatureParsing.parseTypeString(new StringCharacterIterator(signature), StubBuildingVisitor.GUESSING_MAPPER);
   }