diff --git a/clang/lib/Format/UnwrappedLineParser.h b/clang/lib/Format/UnwrappedLineParser.h
--- a/clang/lib/Format/UnwrappedLineParser.h
+++ b/clang/lib/Format/UnwrappedLineParser.h
@@ -117,8 +117,10 @@
   bool parseStructLike();
   void parseConcept();
   void parseRequires();
-  void parseRequiresExpression(unsigned int OriginalLevel);
-  void parseConstraintExpression(unsigned int OriginalLevel);
+  void parseRequiresExpression(unsigned int OriginalLevel,
+                               bool InTrailingRequire = false);
+  void parseConstraintExpression(unsigned int OriginalLevel,
+                                 bool InTrailingRequire = false);
   void parseJavaEnumBody();
   // Parses a record (aka class) as a top level element. If ParseAsExpr is true,
   // parses the record as a child block, i.e. if the class declaration is an
diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -2547,7 +2547,8 @@
   }
 }
 
-void UnwrappedLineParser::parseRequiresExpression(unsigned int OriginalLevel) {
+void UnwrappedLineParser::parseRequiresExpression(unsigned int OriginalLevel,
+                                                  bool InTrailingRequire) {
   // requires (R range)
   if (FormatTok->Tok.is(tok::l_paren)) {
     parseParens();
@@ -2564,12 +2565,12 @@
     parseBlock();
     addUnwrappedLine();
   } else {
-    parseConstraintExpression(OriginalLevel);
+    parseConstraintExpression(OriginalLevel, InTrailingRequire);
   }
 }
 
-void UnwrappedLineParser::parseConstraintExpression(
-    unsigned int OriginalLevel) {
+void UnwrappedLineParser::parseConstraintExpression(unsigned int OriginalLevel,
+                                                    bool InTrailingRequire) {
   // requires Id<T> && Id<T> || Id<T>
   while (
       FormatTok->isOneOf(tok::identifier, tok::kw_requires, tok::coloncolon)) {
@@ -2609,10 +2610,13 @@
       return;
     }
     if (!FormatTok->Tok.isOneOf(tok::ampamp, tok::pipepipe)) {
-      if (FormatTok->Previous &&
-          !FormatTok->Previous->isOneOf(tok::identifier, tok::kw_requires,
-                                        tok::coloncolon)) {
-        addUnwrappedLine();
+      if (FormatTok->Previous) {
+        bool AddLine =
+            !FormatTok->Previous->isOneOf(tok::identifier, tok::kw_requires,
+                                          tok::coloncolon) &&
+            !(InTrailingRequire && FormatTok->Previous->is(tok::r_brace));
+        if (AddLine)
+          addUnwrappedLine();
       }
       if (Style.IndentRequires && OriginalLevel != Line->Level) {
         --Line->Level;
@@ -2630,7 +2634,9 @@
   assert(FormatTok->Tok.is(tok::kw_requires) && "'requires' expected");
 
   unsigned OriginalLevel = Line->Level;
-  if (FormatTok->Previous && FormatTok->Previous->is(tok::greater)) {
+  bool InTrailingRequire =
+      !(FormatTok->Previous && FormatTok->Previous->is(tok::greater));
+  if (!InTrailingRequire) {
     addUnwrappedLine();
     if (Style.IndentRequires) {
       Line->Level++;
@@ -2638,7 +2644,7 @@
   }
   nextToken();
 
-  parseRequiresExpression(OriginalLevel);
+  parseRequiresExpression(OriginalLevel, InTrailingRequire);
 }
 
 bool UnwrappedLineParser::parseEnum() {
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
@@ -16914,6 +16914,49 @@
                Style);
 }
 
+TEST_F(FormatTest, AttachBraceBreaking) {
+  FormatStyle BraceStyle = getLLVMStyle();
+  BraceStyle.BreakBeforeBraces = FormatStyle::BS_Attach;
+  verifyFormat("namespace a {\n"
+               "class A {\n"
+               "  void f() {\n"
+               "    if (true) {\n"
+               "      a();\n"
+               "      b();\n"
+               "    } else {\n"
+               "      a();\n"
+               "    }\n"
+               "  }\n"
+               "  void g() { return; }\n"
+               "};\n"
+               "struct B {\n"
+               "  int x;\n"
+               "};\n"
+               "} // namespace a\n",
+               BraceStyle);
+  verifyFormat("enum X {\n"
+               "  Y = 0,\n"
+               "}\n",
+               BraceStyle);
+  verifyFormat("struct S {\n"
+               "  int Type;\n"
+               "  union {\n"
+               "    int x;\n"
+               "    double y;\n"
+               "  } Value;\n"
+               "  class C {\n"
+               "    MyFavoriteType Value;\n"
+               "  } Class;\n"
+               "}\n",
+               BraceStyle);
+  // https://llvm.org/PR48968
+  verifyFormat("void f() requires requires { a; } {\n"
+               "  a();\n"
+               "  b();\n"
+               "}\n",
+               BraceStyle);
+}
+
 TEST_F(FormatTest, LinuxBraceBreaking) {
   FormatStyle LinuxBraceStyle = getLLVMStyle();
   LinuxBraceStyle.BreakBeforeBraces = FormatStyle::BS_Linux;
@@ -17348,6 +17391,13 @@
                "  }\n"
                "}\n",
                BreakBeforeBraceShortIfs);
+  // https://llvm.org/PR48968
+  verifyFormat("void f() requires requires { a; }\n"
+               "{\n"
+               "  a();\n"
+               "  b();\n"
+               "}\n",
+               BreakBeforeBraceShortIfs);
 }
 
 TEST_F(FormatTest, WhitesmithsBraceBreaking) {
@@ -22483,6 +22533,15 @@
                "}",
                Style);
 
+  // https://llvm.org/PR48968
+  verifyFormat("void f() requires requires {\n"
+               "  a;\n"
+               "} {\n"
+               "  a();\n"
+               "  b();\n"
+               "}\n",
+               Style);
+
   verifyFormat(
       "template <typename T> int g(T i) requires Concept1<I> && Concept2<I> {\n"
       "  //...\n"