Fix #1941

Author: cowtowncoder

release-notes/VERSION

@@ -3,6 +3,12 @@ Project: jackson-databind
 === Releases ===
 ------------------------------------------------------------------------
 
+2.8.11.2 (not yet released)
+
+#1941: `TypeFactory.constructFromCanonical()` throws NPE for Unparameterized
+  generic canonical strings
+ (reported by ayushgp@github)
+
 2.8.11.1 (11-Feb-2018)
 
 #1872: `NullPointerException` in `SubTypeValidator.validateSubType` when

src/main/java/com/fasterxml/jackson/databind/type/TypeFactory.java

@@ -352,7 +352,7 @@ public JavaType constructSpecializedType(JavaType baseType, Class<?> subclass)
         // also: if we start from untyped, not much to save
         do { // bogus loop to be able to break
             if (rawBase == Object.class) {
-                newType = _fromClass(null, subclass, TypeBindings.emptyBindings());
+                newType = _fromClass(null, subclass, EMPTY_BINDINGS);
                 break;
             }
             if (!rawBase.isAssignableFrom(subclass)) {
@@ -363,7 +363,7 @@ public JavaType constructSpecializedType(JavaType baseType, Class<?> subclass)
 
             // (1) Original target type has no generics -- just resolve subtype
             if (baseType.getBindings().isEmpty()) {
-                newType = _fromClass(null, subclass, TypeBindings.emptyBindings());     
+                newType = _fromClass(null, subclass, EMPTY_BINDINGS);     
                 break;
             }
             // (2) A small set of "well-known" List/Map subtypes where can take a short-cut
@@ -893,7 +893,7 @@ public JavaType constructParametricType(Class<?> parametrized, Class<?>... param
         int len = parameterClasses.length;
         JavaType[] pt = new JavaType[len];
         for (int i = 0; i < len; ++i) {
-            pt[i] = _fromClass(null, parameterClasses[i], null);
+            pt[i] = _fromClass(null, parameterClasses[i], EMPTY_BINDINGS);
         }
         return constructParametricType(parametrized, pt);
     }

src/main/java/com/fasterxml/jackson/databind/type/TypeParser.java

@@ -56,7 +56,7 @@ protected JavaType parseType(MyTokenizer tokens)
             // can be comma that separates types, or closing '>'
             tokens.pushBack(token);
         }
-        return _factory._fromClass(null, base, null);
+        return _factory._fromClass(null, base, TypeBindings.emptyBindings());
     }
 
     protected List<JavaType> parseTypes(MyTokenizer tokens)

src/test/java/com/fasterxml/jackson/databind/type/TestTypeFactory.java

@@ -231,6 +231,22 @@ public void testCanonicalNames()
         assertEquals("java.util.EnumMap<com.fasterxml.jackson.databind.type.TestTypeFactory$EnumForCanonical,java.lang.String>",
                 can);
         assertEquals(t, tf.constructFromCanonical(can));
+
+        // [databind#1941]: allow "raw" types too
+
+        t = tf.constructFromCanonical("java.util.List");
+        assertEquals(List.class, t.getRawClass());
+        assertEquals(CollectionType.class, t.getClass());
+        // 01-Mar-2018, tatu: not 100% should we expect type parameters here...
+        //    But currently we do NOT get any
+        /*
+        assertEquals(1, t.containedTypeCount());
+        assertEquals(Object.class, t.containedType(0).getRawClass());
+        */
+        assertEquals(Object.class, t.getContentType().getRawClass());
+        can = t.toCanonical();
+        assertEquals("java.util.List<java.lang.Object>", can);
+        assertEquals(t, tf.constructFromCanonical(can));
     }
 
     // [databind#1768]