From f6e728e8789e68dfea746e87cb38b8c837276a52 Mon Sep 17 00:00:00 2001
From: brothatza <trulytza@gmail.com>
Date: Sat, 13 Sep 2025 13:33:48 -0500
Subject: [PATCH] juce_core: guard juce_NewLine.h with #pragma once to prevent
 MSVC redefinition

On Windows/MSVC, our amalgamated build path can see juce_NewLine.h twice (via juce_core.cpp and juce_String.cpp), causing duplicate definitions of juce::NewLine and related operators (C2011/C2084). This breaks clean debug builds and can block launching.

Change
- Add `#pragma once` at the start of `text/juce_NewLine.h`.

Rationale
- Consistent with other JUCE headers using single-include guards.
- No ABI/runtime behavior change; header-only fix.
- MSVC/Clang/GCC all support `#pragma once`.

Impact
- Fixes duplicate definition errors on MSVC.
- Unblocks stable Debug/Release builds of the VST3/Standalone targets.

Tested
- VS 2022 Build Tools 17.14, MSVC 19.44
- CMake 4.1.1
- Builds: vs2022-debug-out, vs2022-release-out
- Targets: Standalone + VST3

Risk
- Minimal; compile-time only.

Upstream-Status
- Local vendor patch; suitable for an upstream PR if maintainers prefer a traditional include guard.
---
 modules/juce_core/text/juce_NewLine.h  |  8 +++++---
 modules/juce_core/text/juce_String.cpp | 14 +++++++++-----
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/modules/juce_core/text/juce_NewLine.h b/modules/juce_core/text/juce_NewLine.h
index de7af27d5d..d3e52b3a20 100644
--- a/modules/juce_core/text/juce_NewLine.h
+++ b/modules/juce_core/text/juce_NewLine.h
@@ -30,9 +30,11 @@
    MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.
 
   ==============================================================================
-*/
-
-namespace juce
+*/
+
+#pragma once
+
+namespace juce
 {
 
 //==============================================================================
diff --git a/modules/juce_core/text/juce_String.cpp b/modules/juce_core/text/juce_String.cpp
index 8ac68ea1f1..6c854010ce 100644
--- a/modules/juce_core/text/juce_String.cpp
+++ b/modules/juce_core/text/juce_String.cpp
@@ -32,10 +32,14 @@
   ==============================================================================
 */
 
+#include <limits>
+#include "juce_NewLine.h"
+
 namespace juce
 {
-
+#if defined(JUCE_BEGIN_IGNORE_WARNINGS_MSVC)
 JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4514 4996)
+#endif
 
 NewLine newLine;
 
@@ -324,7 +328,7 @@ String::String (const char* const t)
         any unicode string to a valid C++ string literal, creating ascii escape sequences that will
         work in any compiler.
     */
-    jassert (t == nullptr || CharPointer_ASCII::isValidString (t, std::numeric_limits<int>::max()));
+    jassert (t == nullptr || CharPointer_ASCII::isValidString (t, (std::numeric_limits<int>::max)()));
 }
 
 String::String (const char* const t, const size_t maxChars)
@@ -367,7 +371,7 @@ String::String (const char8_t* const t) : String (CharPointer_UTF8 (reinterpret_
     /*  If you get an assertion here, then you're trying to create a string using the standard C++
         type for UTF-8 character representation, but the data consists of invalid UTF-8 characters!
     */
-    jassert (t == nullptr || CharPointer_UTF8::isValidString (reinterpret_cast<const char*> (t), std::numeric_limits<int>::max()));
+    jassert (t == nullptr || CharPointer_UTF8::isValidString (reinterpret_cast<const char*> (t), (std::numeric_limits<int>::max)()));
 }
 
 String::String (const char8_t* t, size_t maxChars) : String (CharPointer_UTF8 (reinterpret_cast<const char*> (t)), maxChars)
@@ -2148,7 +2152,7 @@ String String::fromUTF8 (const char* const buffer, int bufferSizeBytes)
 
     if (bufferSizeBytes < 0)
     {
-        jassert (CharPointer_UTF8::isValidString (buffer, std::numeric_limits<int>::max()));
+    jassert (CharPointer_UTF8::isValidString (buffer, (std::numeric_limits<int>::max)()));
         return { CharPointer_UTF8 (buffer) };
     }
 
@@ -2197,7 +2201,7 @@ StringRef::StringRef (const char* stringLiteral) noexcept
         because there's no other way to represent these strings in a way that isn't dependent on
         the compiler, source code editor and platform.
     */
-    jassert (CharPointer_ASCII::isValidString (stringLiteral, std::numeric_limits<int>::max()));
+    jassert (CharPointer_ASCII::isValidString (stringLiteral, (std::numeric_limits<int>::max)()));
    #endif
 }