Index: clang/lib/Format/UnwrappedLineFormatter.cpp
===================================================================
--- clang/lib/Format/UnwrappedLineFormatter.cpp
+++ clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -449,7 +449,7 @@
 
   unsigned tryMergeCSharpPropertyAccessor(
       SmallVectorImpl<AnnotatedLine *>::const_iterator I,
-      SmallVectorImpl<AnnotatedLine *>::const_iterator E, unsigned /*Limit*/) {
+      SmallVectorImpl<AnnotatedLine *>::const_iterator E, unsigned Limit) {
 
     auto CurrentLine = I;
     // Does line start with `{`
@@ -459,6 +459,7 @@
 
     unsigned MergedLines = 0;
     bool HasGetOrSet = false;
+    bool HasDefaultValue = false;
     while (CurrentLine != E) {
       bool LineIsGetOrSet = isMergeablePropertyAccessor(*CurrentLine);
       HasGetOrSet = HasGetOrSet || LineIsGetOrSet;
@@ -471,18 +472,34 @@
       if (Tok && Tok->is(tok::r_brace)) {
         ++CurrentLine;
         ++MergedLines;
-        // See if the next line is a default value so that we can merge `{ get;
-        // set } = 0`
+        // See if the next line is a default value so that we can merge
+        // `{ get; set } = 0`
         if (CurrentLine != E && (*CurrentLine)->First &&
             (*CurrentLine)->First->is(tok::equal)) {
           ++MergedLines;
+          HasDefaultValue = true;
         }
         break;
       }
-      // Not a '}' or a get/set line so do not merege lines.
+      // Not a '}' or a get/set line so do not merge lines.
       return 0;
     }
 
+    // If the Limit is broken, split the default value onto a new line and
+    // indent it.
+    //
+    // This is a crude heuristic that works for cases like:
+    //  `MyVeryLongTypeName Name { get; set } = new MyVeryLongTypeName();`
+    // A more robust or general solution would be good.
+    unsigned TotalLength = 0;
+    for (unsigned Index = 0; Index < MergedLines; ++Index) {
+      TotalLength += I[Index]->Last->TotalLength;
+    }
+    if (TotalLength > Limit && HasDefaultValue) {
+      I[MergedLines]->Level += 1;
+      --MergedLines;
+    }
+
     return HasGetOrSet ? MergedLines : 0;
   }
 
Index: clang/unittests/Format/FormatTestCSharp.cpp
===================================================================
--- clang/unittests/Format/FormatTestCSharp.cpp
+++ clang/unittests/Format/FormatTestCSharp.cpp
@@ -565,6 +565,10 @@
   verifyFormat("int Value { get; set; }", Style);
   verifyFormat("int Value { get; set; } = 0", Style);
   verifyFormat("int Value { internal get; internal set; }", Style);
+  verifyFormat(R"(//
+MyVeryLongTypeName MyVeryLongVariableName { internal get; internal set; }
+  = new MyVeryLongTypeName();)",
+               Style);
 
   // Do not wrap expression body definitions.
   verifyFormat(R"(//