diff --git a/CoreFoundation/Parsing.subproj/CFXMLInterface.c b/CoreFoundation/Parsing.subproj/CFXMLInterface.c
index c21e354c9f..2f609f6296 100644
--- a/CoreFoundation/Parsing.subproj/CFXMLInterface.c
+++ b/CoreFoundation/Parsing.subproj/CFXMLInterface.c
@@ -435,7 +435,7 @@ void _CFXMLNodeSetPrivateData(_CFXMLNodePtr node, void* data) {
     if (!node) {
         return;
     }
-    
+
     ((xmlNodePtr)node)->_private = data;
 }
 
@@ -459,6 +459,7 @@ static inline xmlChar* _getQName(xmlNodePtr node) {
     const xmlChar* ncname = node->name;
     
     switch (node->type) {
+        case XML_DOCUMENT_NODE:
         case XML_NOTATION_NODE:
         case XML_DTD_NODE:
         case XML_ELEMENT_DECL:
diff --git a/CoreFoundation/String.subproj/CFString.c b/CoreFoundation/String.subproj/CFString.c
index 8ec33fee79..bab1ddafdb 100644
--- a/CoreFoundation/String.subproj/CFString.c
+++ b/CoreFoundation/String.subproj/CFString.c
@@ -1468,7 +1468,7 @@ CF_PRIVATE CFStringRef __CFStringCreateImmutableFunnel3(
             if (noCopy) {
 
                 size = sizeof(void *);				// Pointer to the buffer
-                if ((0) || (contentsDeallocator != alloc && contentsDeallocator != kCFAllocatorNull)) {
+                if (contentsDeallocator != alloc && contentsDeallocator != kCFAllocatorNull) {
                     size += sizeof(void *);	// The contentsDeallocator
                 }
                 if (!hasLengthByte) size += sizeof(CFIndex);	// Explicit length
@@ -1480,12 +1480,14 @@ CF_PRIVATE CFStringRef __CFStringCreateImmutableFunnel3(
                 useInlineData = true;
                 size = numBytes;
 
-                if (hasLengthByte || (encoding != kCFStringEncodingUnicode && __CFCanUseLengthByte(numBytes))) {
+                if (hasLengthByte) {
                     useLengthByte = true;
-                    if (!hasLengthByte) size += 1;
+                } else if (encoding != kCFStringEncodingUnicode && __CFCanUseLengthByte(numBytes)) {
+                    useLengthByte = true;
+                    size += 1;
                 } else {
                     size += sizeof(CFIndex);	// Explicit length
-                }	    
+                }
                 if (hasNullByte || encoding != kCFStringEncodingUnicode) {
                     useNullByte = true;
                     size += 1;
diff --git a/Foundation/XMLNode.swift b/Foundation/XMLNode.swift
index cad0ced828..b885388983 100644
--- a/Foundation/XMLNode.swift
+++ b/Foundation/XMLNode.swift
@@ -312,9 +312,13 @@ open class XMLNode: NSObject, NSCopying {
             return _CFXMLNodeCopyName(_xmlNode)?._swiftObject
         }
         set {
-            if case .namespace = kind {
+            switch kind {
+            case .document:
+                // As with Darwin, ignore the name when the node is document.
+                break
+            case .namespace:
                 _CFXMLNamespaceSetPrefix(_xmlNode, newValue, Int64(newValue?.utf8.count ?? 0))
-            } else {
+            default:
                 if let newName = newValue {
                     _CFXMLNodeSetName(_xmlNode, newName)
                 } else {
diff --git a/TestFoundation/TestXMLDocument.swift b/TestFoundation/TestXMLDocument.swift
index 41dd38c743..6437960ef4 100644
--- a/TestFoundation/TestXMLDocument.swift
+++ b/TestFoundation/TestXMLDocument.swift
@@ -35,6 +35,7 @@ class TestXMLDocument : LoopbackServerTest {
             ("test_removeNamespace", test_removeNamespace),
             ("test_optionPreserveAll", test_optionPreserveAll),
             ("test_rootElementRetainsDocument", test_rootElementRetainsDocument),
+            ("test_sr10776_documentName", test_SR10776_documentName),
         ]
     }
 
@@ -544,6 +545,13 @@ class TestXMLDocument : LoopbackServerTest {
 
         XCTAssertEqual(try? test(), "plans")
     }
+    func test_SR10776_documentName() {
+        let doc = XMLDocument(rootElement: nil)
+        XCTAssertNil(doc.name)
+
+        doc.name = "name"
+        XCTAssertNil(doc.name) // `name` of XMLDocument is always nil.
+    }
 }
 
 fileprivate extension XMLNode {