Index: clang/lib/AST/ExprConstant.cpp
===================================================================
--- clang/lib/AST/ExprConstant.cpp
+++ clang/lib/AST/ExprConstant.cpp
@@ -15234,6 +15234,10 @@
   assert(!isValueDependent() &&
          "Expression evaluator can't be called on a dependent expression.");
   ExprTimeTraceScope TimeScope(this, Ctx, "EvaluateAsBooleanCondition");
+  if (isa<StringLiteral>(this)) {
+    Result = true;
+    return true;
+  }
   EvalResult Scratch;
   return EvaluateAsRValue(Scratch, Ctx, InConstantContext) &&
          HandleConversionToBool(Scratch.Val, Result);
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -15226,11 +15226,18 @@
   if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(LHSExpr)) {
     if (Bop->getOpcode() == BO_LAnd) {
       // If it's "a && b || 0" don't warn since the precedence doesn't matter.
-      if (EvaluatesAsFalse(S, RHSExpr))
+      if (isa<IntegerLiteral, FloatingLiteral, CharacterLiteral,
+              CXXBoolLiteralExpr, CXXNullPtrLiteralExpr, FixedPointLiteral>(
+              RHSExpr) &&
+          EvaluatesAsFalse(S, RHSExpr))
         return;
+      Expr *LLHS = Bop->getLHS()->IgnoreParenImpCasts();
       // If it's "1 && a || b" don't warn since the precedence doesn't matter.
-      if (!EvaluatesAsTrue(S, Bop->getLHS()))
-        return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop);
+      if (isa<IntegerLiteral, FloatingLiteral, CharacterLiteral,
+              CXXBoolLiteralExpr, FixedPointLiteral, StringLiteral>(LLHS) &&
+          EvaluatesAsTrue(S, LLHS))
+        return;
+      return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop);
     } else if (Bop->getOpcode() == BO_LOr) {
       if (BinaryOperator *RBop = dyn_cast<BinaryOperator>(Bop->getRHS())) {
         // If it's "a || b && 1 || c" we didn't warn earlier for
@@ -15248,11 +15255,18 @@
   if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(RHSExpr)) {
     if (Bop->getOpcode() == BO_LAnd) {
       // If it's "0 || a && b" don't warn since the precedence doesn't matter.
-      if (EvaluatesAsFalse(S, LHSExpr))
+      if (isa<IntegerLiteral, FloatingLiteral, CharacterLiteral,
+              CXXBoolLiteralExpr, CXXNullPtrLiteralExpr, FixedPointLiteral>(
+              LHSExpr) &&
+          EvaluatesAsFalse(S, LHSExpr))
         return;
       // If it's "a || b && 1" don't warn since the precedence doesn't matter.
-      if (!EvaluatesAsTrue(S, Bop->getRHS()))
-        return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop);
+      Expr *RRHS = Bop->getRHS()->IgnoreParenImpCasts();
+      if (isa<IntegerLiteral, FloatingLiteral, CharacterLiteral,
+              CXXBoolLiteralExpr, FixedPointLiteral, StringLiteral>(RRHS) &&
+          EvaluatesAsTrue(S, RRHS))
+        return;
+      return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop);
     }
   }
 }
Index: clang/test/Sema/logical-op-parentheses.c
===================================================================
--- clang/test/Sema/logical-op-parentheses.c
+++ clang/test/Sema/logical-op-parentheses.c
@@ -8,6 +8,7 @@
 #endif
 
 void logical_op_parentheses(unsigned i) {
+	const unsigned t = 1;
   (void)(i ||
              i && i);
 #ifndef SILENCE
@@ -17,8 +18,31 @@
   // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
   // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:20-[[@LINE-6]]:20}:")"
 
-  (void)(i || i && "w00t");
+  (void)(t ||
+             t && t);
+#ifndef SILENCE
+  // expected-warning@-2 {{'&&' within '||'}}
+  // expected-note@-3 {{place parentheses around the '&&' expression to silence this warning}}
+#endif
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:20-[[@LINE-6]]:20}:")"
+
+  (void)(t && 
+             t || t);
+#ifndef SILENCE
+  // expected-warning@-3 {{'&&' within '||'}}
+  // expected-note@-4 {{place parentheses around the '&&' expression to silence this warning}}
+#endif
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:10-[[@LINE-6]]:10}:"("
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:15-[[@LINE-6]]:15}:")"
+	
+	(void)(i || i && "w00t");
   (void)("w00t" && i || i);
+  (void)("w00t" && t || t);
+  (void)(t && t || 0);
+  (void)(1 && t || t);
+  (void)(0 || t && t);
+  (void)(t || t && 1);
 
   (void)(i || i && "w00t" || i);
 #ifndef SILENCE
Index: clang/test/Sema/logical-op-parentheses.cpp
===================================================================
--- /dev/null
+++ clang/test/Sema/logical-op-parentheses.cpp
@@ -0,0 +1,66 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s -DSILENCE
+// RUN: %clang_cc1 -fsyntax-only -verify %s -Wlogical-op-parentheses
+// RUN: %clang_cc1 -fsyntax-only -verify %s -Wparentheses
+// RUN: %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits %s -Wlogical-op-parentheses 2>&1 | FileCheck %s
+
+#ifdef SILENCE
+// expected-no-diagnostics
+#endif
+
+void logical_op_parentheses(unsigned i) {
+	constexpr bool t = 1;
+  (void)(i ||
+             i && i);
+#ifndef SILENCE
+  // expected-warning@-2 {{'&&' within '||'}}
+  // expected-note@-3 {{place parentheses around the '&&' expression to silence this warning}}
+#endif
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:20-[[@LINE-6]]:20}:")"
+
+  static_assert(t ||
+             t && t);
+#ifndef SILENCE
+  // expected-warning@-2 {{'&&' within '||'}}
+  // expected-note@-3 {{place parentheses around the '&&' expression to silence this warning}}
+#endif
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:14-[[@LINE-5]]:14}:"("
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:20-[[@LINE-6]]:20}:")"
+
+  static_assert(t && 
+             t || t);
+#ifndef SILENCE
+  // expected-warning@-3 {{'&&' within '||'}}
+  // expected-note@-4 {{place parentheses around the '&&' expression to silence this warning}}
+#endif
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:17-[[@LINE-6]]:17}:"("
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:15-[[@LINE-6]]:15}:")"
+	
+	(void)(i || i && "w00t");
+  (void)("w00t" && i || i);
+  (void)("w00t" && t || t);
+  static_assert(t && t || 0);
+  static_assert(1 && t || t);
+  static_assert(0 || t && t);
+  static_assert(t || t && 1);
+
+  (void)(i || i && "w00t" || i);
+#ifndef SILENCE
+  // expected-warning@-2 {{'&&' within '||'}}
+  // expected-note@-3 {{place parentheses around the '&&' expression to silence this warning}}
+#endif
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:15-[[@LINE-5]]:15}:"("
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:26-[[@LINE-6]]:26}:")"
+
+  (void)(i || "w00t" && i || i);
+#ifndef SILENCE
+  // expected-warning@-2 {{'&&' within '||'}}
+  // expected-note@-3 {{place parentheses around the '&&' expression to silence this warning}}
+#endif
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-5]]:15-[[@LINE-5]]:15}:"("
+  // CHECK: fix-it:"{{.*}}":{[[@LINE-6]]:26-[[@LINE-6]]:26}:")"
+
+  (void)(i && i || 0);
+  (void)(0 || i && i);
+}
+