Fix #667

Author: cowtowncoder

release-notes/VERSION

@@ -4,6 +4,10 @@ Project: jackson-databind
 === Releases ===
 ------------------------------------------------------------------------
 
+2.5.1 (not yet released)
+
+#667: Problem with bogus conflict between single-arg-String vs `CharSequence` constructor
+
 2.5.0 (01-Jan-2015)
 
 #47: Support `@JsonValue` for (Map) key serialization 

src/main/java/com/fasterxml/jackson/databind/deser/impl/CreatorCollector.java

@@ -280,16 +280,36 @@ protected void verifyNonDup(AnnotatedWithParams newOne, int typeIndex, boolean e
         AnnotatedWithParams oldOne = _creators[typeIndex];
         // already had an explicitly marked one?
         if (oldOne != null) {
+            boolean verify;
+
             if ((_explicitCreators & mask) != 0) { // already had explicitly annotated, leave as-is
                 // but skip, if new one not annotated
                 if (!explicit) {
                     return;
                 }
+                // both explicit: verify
+                verify = true;
+            } else {
+                // otherwise only verify if neither explicitly annotated.
+                verify = !explicit;
             }
+
             // one more thing: ok to override in sub-class
-            if (oldOne.getClass() == newOne.getClass()) {
-                throw new IllegalArgumentException("Conflicting "+TYPE_DESCS[typeIndex]
-                        +" creators: already had explicitly marked "+oldOne+", encountered "+newOne);
+            if (verify && (oldOne.getClass() == newOne.getClass())) {
+                // [databind#667]: avoid one particular class of bogus problems
+                Class<?> oldType = oldOne.getRawParameterType(0);
+                Class<?> newType = newOne.getRawParameterType(0);
+
+                if (oldType == newType) {
+                    throw new IllegalArgumentException("Conflicting "+TYPE_DESCS[typeIndex]
+                            +" creators: already had explicitly marked "+oldOne+", encountered "+newOne);
+                }
+                // otherwise, which one to choose?
+                if (newType.isAssignableFrom(oldType)) {
+                    // new type more generic, use old
+                    return;
+                }
+                // new type more specific, use it
             }
         }
         if (explicit) {

src/test/java/com/fasterxml/jackson/databind/deser/TestJdkTypes.java

@@ -420,6 +420,12 @@ public void testByteBuffer() throws Exception
         assertEquals(0, result.remaining());
     }
 
+    public void testStringBuilder() throws Exception
+    {
+        StringBuilder sb = MAPPER.readValue(quote("abc"), StringBuilder.class);
+        assertEquals("abc", sb.toString());
+    }
+    
     // [Issue#429]
     public void testStackTraceElementWithCustom() throws Exception
     {