From 2738f3a537fc57aba5e40d529bc11222b0cf9e72 Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Sun, 5 Aug 2018 22:02:20 +0100
Subject: [PATCH] Rewrite archiving/unarchiving of Lua strings for netgames.
This now means:
* Lua strings longer than 1024 chars can now be read properly without awful crashes
* Lua strings with embedded zeros can be written/read without truncating anything (hopefully)
---
src/lua_script.c | 32 ++++++++++++++++++++++++++++----
1 file changed, 28 insertions(+), 4 deletions(-)
diff --git a/src/lua_script.c b/src/lua_script.c
index 67ce77c533..5561094ad7 100644
--- a/src/lua_script.c
+++ b/src/lua_script.c
@@ -526,9 +526,23 @@ static UINT8 ArchiveValue(int TABLESINDEX, int myindex)
break;
}
case LUA_TSTRING:
+ {
+ UINT16 len = (UINT16)lua_objlen(gL, myindex); // get length of string, including embedded zeros
+ const char *s = lua_tostring(gL, myindex);
+ UINT16 i = 0;
WRITEUINT8(save_p, ARCH_STRING);
- WRITESTRING(save_p, lua_tostring(gL, myindex));
+ // if you're wondering why we're writing a string to save_p this way,
+ // it turns out that Lua can have embedded zeros ('\0') in the strings,
+ // so we can't use WRITESTRING as that cuts off when it finds a '\0'.
+ // Saving the size of the string also allows us to get the size of the string on the other end,
+ // fixing the awful crashes previously encountered for reading strings longer than 1024
+ // (yes I know that's kind of a stupid thing to care about, but it'd be evil to trim or ignore them?)
+ // -- Monster Iestyn 05/08/18
+ WRITEUINT16(save_p, len); // save size of string
+ while (i < len)
+ WRITECHAR(save_p, s[i++]); // write chars individually, including the embedded zeros
break;
+ }
case LUA_TTABLE:
{
boolean found = false;
@@ -809,9 +823,19 @@ static UINT8 UnArchiveValue(int TABLESINDEX)
break;
case ARCH_STRING:
{
- char value[1024];
- READSTRING(save_p, value);
- lua_pushstring(gL, value);
+ UINT16 len = READUINT16(save_p); // length of string, including embedded zeros
+ char *value;
+ UINT16 i = 0;
+ // See my comments in the ArchiveValue function;
+ // it's much the same for reading strings as writing them!
+ // (i.e. we can't use READSTRING either)
+ // -- Monster Iestyn 05/08/18
+ value = malloc(len); // make temp buffer of size len
+ // now read the actual string
+ while (i < len)
+ value[i++] = READCHAR(save_p); // read chars individually, including the embedded zeros
+ lua_pushlstring(gL, value, len); // push the string (note: this function supports embedded zeros)
+ free(value); // free the buffer
break;
}
case ARCH_TABLE:
--
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