From 94d74449f36b5750f1d1450b02c3817f179211b1 Mon Sep 17 00:00:00 2001
From: terencehill <piuntn@gmail.com>
Date: Sat, 10 Feb 2024 12:50:09 +0100
Subject: [PATCH] Fix string length checks in world.qc and add
 VM_TEMPSTRING_MAXSIZE

---
 qcsrc/lib/registry.qh |  2 +-
 qcsrc/lib/string.qh   |  3 +++
 qcsrc/server/world.qc | 16 ++++++++++------
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/qcsrc/lib/registry.qh b/qcsrc/lib/registry.qh
index be67847a4..a610df204 100644
--- a/qcsrc/lib/registry.qh
+++ b/qcsrc/lib/registry.qh
@@ -184,7 +184,7 @@ void Registry_send(string id, string hash);
 			if (++group_idx < 50) /* this is to reduce strlen calls */ \
 				continue; \
 			int group_len = strlen(group); \
-			if (str_len + 1 + group_len >= 16383) /* exceeding max string length? */ \
+			if (str_len + 1 + group_len >= VM_TEMPSTRING_MAXSIZE) \
 			{ \
 				/* keep previous digests and replace current string with its digest */ \
 				s = strcat(substring(s, 0, digests_len), ":", digest_hex("MD4", s)); \
diff --git a/qcsrc/lib/string.qh b/qcsrc/lib/string.qh
index 3c39b7c0b..72673b235 100644
--- a/qcsrc/lib/string.qh
+++ b/qcsrc/lib/string.qh
@@ -4,6 +4,9 @@
 #include "sort.qh"
 #include "oo.qh"
 
+// this is not exactly 16KiB (16384 bytes) because one byte is reserved for the \0 terminator
+#define VM_TEMPSTRING_MAXSIZE 16383
+
 // string logic
 //
 // true: is truthy
diff --git a/qcsrc/server/world.qc b/qcsrc/server/world.qc
index 04706f615..7bbbfa0dd 100644
--- a/qcsrc/server/world.qc
+++ b/qcsrc/server/world.qc
@@ -332,8 +332,11 @@ void cvar_changes_init()
 
 		if(adding)
 		{
+			if (cvar_changes == "")
+				cvar_changes = "// this server runs at modified server settings:\n";
+
 			cvar_changes = strcat(cvar_changes, k, " \"", v, "\" // \"", d, "\"\n");
-			if(strlen(cvar_changes) > 16384)
+			if(strlen(cvar_changes) >= VM_TEMPSTRING_MAXSIZE)
 			{
 				cvar_changes = "// too many settings have been changed to show them here\n";
 				adding = 0;
@@ -546,8 +549,11 @@ void cvar_changes_init()
 
 		if(pureadding)
 		{
+			if (cvar_purechanges == "")
+				cvar_purechanges = "// this server runs at modified gameplay settings:\n";
+
 			cvar_purechanges = strcat(cvar_purechanges, k, " \"", v, "\" // \"", d, "\"\n");
-			if(strlen(cvar_purechanges) > 16384)
+			if(strlen(cvar_purechanges) >= VM_TEMPSTRING_MAXSIZE)
 			{
 				cvar_purechanges = "// too many settings have been changed to show them here\n";
 				pureadding = 0;
@@ -562,15 +568,13 @@ void cvar_changes_init()
 		// though.
 	}
 	buf_del(h);
+
 	if(cvar_changes == "")
 		cvar_changes = "// this server runs at default server settings\n";
-	else
-		cvar_changes = strcat("// this server runs at modified server settings:\n", cvar_changes);
 	cvar_changes = strzone(cvar_changes);
+
 	if(cvar_purechanges == "")
 		cvar_purechanges = "// this server runs at default gameplay settings\n";
-	else
-		cvar_purechanges = strcat("// this server runs at modified gameplay settings:\n", cvar_purechanges);
 	cvar_purechanges = strzone(cvar_purechanges);
 }
 
-- 
2.39.2