Index: clang/lib/Format/Format.cpp
===================================================================
--- clang/lib/Format/Format.cpp
+++ clang/lib/Format/Format.cpp
@@ -1918,10 +1918,13 @@
         assert(Next || Token == Line->Last);
         if (!Next && NextLine)
           Next = NextLine->First;
-        const auto Start =
-            Next && Next->NewlinesBefore == 0 && Next->isNot(tok::eof)
-                ? Token->Tok.getLocation()
-                : Token->WhitespaceRange.getBegin();
+        SourceLocation Start;
+        if (Next && Next->NewlinesBefore == 0 && Next->isNot(tok::eof)) {
+          Start = Token->Tok.getLocation();
+          Next->WhitespaceRange = Token->WhitespaceRange;
+        } else {
+          Start = Token->WhitespaceRange.getBegin();
+        }
         const auto Range =
             CharSourceRange::getCharRange(Start, Token->Tok.getEndLoc());
         cantFail(Result.add(tooling::Replacement(SourceMgr, Range, "")));
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -26006,6 +26006,17 @@
                "}",
                Style);
 
+  verifyFormat("while (0)\n"
+               "  if (a)\n"
+               "    return b;\n"
+               "return a;",
+               "while (0) {\n"
+               "  if (a) {\n"
+               "    return b;\n"
+               "}}\n"
+               "return a;",
+               Style);
+
   Style.ColumnLimit = 65;
   verifyFormat("if (condition) {\n"
                "  ff(Indices,\n"