diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -342,21 +342,6 @@
                  ? 1
                  : 0;
     }
-    // Try to merge either empty or one-line block if is precedeed by control
-    // statement token
-    if (TheLine->First->is(tok::l_brace) && TheLine->First == TheLine->Last &&
-        I != AnnotatedLines.begin() &&
-        I[-1]->First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for)) {
-      unsigned MergedLines = 0;
-      if (Style.AllowShortBlocksOnASingleLine != FormatStyle::SBS_Never) {
-        MergedLines = tryMergeSimpleBlock(I - 1, E, Limit);
-        // If we managed to merge the block, discard the first merged line
-        // since we are merging starting from I.
-        if (MergedLines > 0)
-          --MergedLines;
-      }
-      return MergedLines;
-    }
     // Don't merge block with left brace wrapped after ObjC special blocks
     if (TheLine->First->is(tok::l_brace) && I != AnnotatedLines.begin() &&
         I[-1]->First->is(tok::at) && I[-1]->First->Next) {
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -606,6 +606,12 @@
   verifyFormat("if CONSTEXPR (true) { f(); }", AllowSimpleBracedStatements);
   verifyFormat("while (true) { f(); }", AllowSimpleBracedStatements);
   verifyFormat("for (;;) { f(); }", AllowSimpleBracedStatements);
+  verifyFormat("if (true) { fffffffffffffffffffffff(); }",
+               AllowSimpleBracedStatements);
+  verifyFormat("if (true) {\n"
+               "  ffffffffffffffffffffffff();\n"
+               "}",
+               AllowSimpleBracedStatements);
   verifyFormat("if (true) {\n"
                "  ffffffffffffffffffffffffffffffffffffffffffffffffffffff();\n"
                "}",
@@ -681,6 +687,13 @@
   verifyFormat("if CONSTEXPR (true) { f(); }", AllowSimpleBracedStatements);
   verifyFormat("while (true) { f(); }", AllowSimpleBracedStatements);
   verifyFormat("for (;;) { f(); }", AllowSimpleBracedStatements);
+  verifyFormat("if (true) { fffffffffffffffffffffff(); }",
+               AllowSimpleBracedStatements);
+  verifyFormat("if (true)\n"
+               "{\n"
+               "  ffffffffffffffffffffffff();\n"
+               "}",
+               AllowSimpleBracedStatements);
   verifyFormat("if (true)\n"
                "{\n"
                "  ffffffffffffffffffffffffffffffffffffffffffffffffffffff();\n"
@@ -745,7 +758,9 @@
   Style.BreakBeforeBraces = FormatStyle::BS_Allman;
   EXPECT_EQ("#define A                                                  \\\n"
             "  if (HANDLEwernufrnuLwrmviferuvnierv)                     \\\n"
-            "  { RET_ERR1_ANUIREUINERUIFNIOAerwfwrvnuier; }\n"
+            "  {                                                        \\\n"
+            "    RET_ERR1_ANUIREUINERUIFNIOAerwfwrvnuier;               \\\n"
+            "  }\n"
             "X;",
             format("#define A \\\n"
                    "   if (HANDLEwernufrnuLwrmviferuvnierv) { \\\n"