Don't set HasFormFeedBefore unless KeepFormFeed is true

Author: owenca

clang/lib/Format/FormatTokenLexer.cpp

@@ -1186,7 +1186,7 @@ FormatToken *FormatTokenLexer::getNextToken() {
         Column = 0;
         break;
       case '\f':
-        if (!InEscape && !FormatTok->HasFormFeedBefore &&
+        if (Style.KeepFormFeed && !FormatTok->HasFormFeedBefore &&
             // The form feed is immediately preceded and followed by a newline.
             i > 0 && Text[i - 1] == '\n' &&
             ((i + 1 < e && Text[i + 1] == '\n') ||

clang/lib/Format/WhitespaceManager.cpp

@@ -1713,7 +1713,7 @@ void WhitespaceManager::appendNewlineText(std::string &Text, const Change &C) {
   StringRef Newline = UseCRLF ? "\r\n" : "\n";
   Text.append(Newline);
 
-  if (Style.KeepFormFeed && C.Tok->HasFormFeedBefore)
+  if (C.Tok->HasFormFeedBefore)
     Text.append("\f");
 
   for (unsigned I = 1; I < C.NewlinesBefore; ++I)

clang/unittests/Format/FormatTest.cpp

@@ -28252,16 +28252,21 @@ TEST_F(FormatTest, KeepFormFeed) {
                "void f();",
                Style);
 
-  Style.MaxEmptyLinesToKeep = 3;
-  verifyFormat("int i;\n"
-               "\f\n"
-               "\n"
+  constexpr StringRef FormFeedBeforeEmptyLine{"int i;\n"
+                                              "\f\n"
+                                              "\n"
+                                              "void f();"};
+  Style.MaxEmptyLinesToKeep = 2;
+  verifyFormat(FormFeedBeforeEmptyLine,
+               "int i;\n"
                "\n"
+               "\f\n"
                "void f();",
+               Style);
+  verifyFormat(FormFeedBeforeEmptyLine,
                "int i;\n"
-               "\n"
                "\f\n"
-               "\n"
+               "\f\n"
                "void f();",
                Style);
 }