From a469fa2cfc9f0202fa7631a80f67bffbda01fa2e Mon Sep 17 00:00:00 2001
From: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Date: Sun, 19 Mar 2023 14:57:10 -0700
Subject: [PATCH] Add assertion about header-dest relation to strcpy_insitu

May improve static analysis behavior for #555.
---
 src/pugixml.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index beec50c..2f15073 100644
--- a/src/pugixml.cpp
+++ b/src/pugixml.cpp
@@ -2374,6 +2374,8 @@ PUGI_IMPL_NS_BEGIN
 	template <typename String, typename Header>
 	PUGI_IMPL_FN bool strcpy_insitu(String& dest, Header& header, uintptr_t header_mask, const char_t* source, size_t source_length)
 	{
+		assert((header & header_mask) == 0 || dest); // header bit indicates whether dest was previously allocated
+
 		if (source_length == 0)
 		{
 			// empty string and null pointer are equivalent, so just deallocate old memory
@@ -4408,7 +4410,7 @@ PUGI_IMPL_NS_BEGIN
 	template <typename String, typename Header>
 	PUGI_IMPL_FN void node_copy_string(String& dest, Header& header, uintptr_t header_mask, char_t* source, Header& source_header, xml_allocator* alloc)
 	{
-		assert(!dest && (header & header_mask) == 0);
+		assert(!dest && (header & header_mask) == 0); // copies are performed into fresh nodes
 
 		if (source)
 		{