diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index f2ed027b2c047..ac8c0c8fd0ec0 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -986,8 +986,10 @@ class LineJoiner {
   void join(AnnotatedLine &A, const AnnotatedLine &B) {
     assert(!A.Last->Next);
     assert(!B.First->Previous);
-    if (B.Affected)
+    if (B.Affected || B.LeadingEmptyLinesAffected) {
+      assert(B.Affected || A.Last->Children.empty());
       A.Affected = true;
+    }
     A.Last->Next = B.First;
     B.First->Previous = A.Last;
     B.First->CanBreakBefore = true;
diff --git a/clang/unittests/Format/FormatTestSelective.cpp b/clang/unittests/Format/FormatTestSelective.cpp
index 624684c7a079b..0b7ac21fd33d3 100644
--- a/clang/unittests/Format/FormatTestSelective.cpp
+++ b/clang/unittests/Format/FormatTestSelective.cpp
@@ -41,6 +41,11 @@ TEST_F(FormatTestSelective, RemovesTrailingWhitespaceOfFormattedLine) {
   EXPECT_EQ("int a;", format("int a;         ", 0, 0));
   EXPECT_EQ("int a;\n", format("int a;  \n   \n   \n ", 0, 0));
   EXPECT_EQ("int a;\nint b;    ", format("int a;  \nint b;    ", 0, 0));
+
+  EXPECT_EQ("void f() {}", format("void f() {\n"
+                                  "  \n"
+                                  "}",
+                                  11, 0));
 }
 
 TEST_F(FormatTestSelective, FormatsCorrectRegionForLeadingWhitespace) {