Lua API: Log incorrect parameter types as error (#9954)

Incorrect parameter types are logged as errors, taking coercion into account.
This is a workaround to ensure mod compatibility.
Duplicate warnings are ignored per server instance.

diff --git a/src/script/common/c_converter.cpp b/src/script/common/c_converter.cpp
index 279d8b1a5ecc665a5e087229480960f0618e8c6a..de0cdfbf49064da7d56711cec4c38ab79642acea 100644 (file)
--- a/src/script/common/c_converter.cpp
+++ b/src/script/common/c_converter.cpp
@@ -28,6 +28,7 @@ extern "C" {
 #include "common/c_converter.h"
 #include "common/c_internal.h"
 #include "constants.h"
+#include <set>
 
 
 #define CHECK_TYPE(index, name, type) { \
@@ -458,11 +459,36 @@ size_t read_stringlist(lua_State *L, int index, std::vector<std::string> *result
 
 bool check_field_or_nil(lua_State *L, int index, int type, const char *fieldname)
 {
-       if (lua_isnil(L, index))
+       static thread_local std::set<u64> warned_msgs;
+
+       int t = lua_type(L, index);
+       if (t == LUA_TNIL)
                return false;
 
-       CHECK_TYPE(index, std::string("field \"") + fieldname + '"', type);
-       return true;
+       if (t == type)
+               return true;
+
+       // Check coercion types
+       if (type == LUA_TNUMBER) {
+               if (lua_isnumber(L, index))
+                       return true;
+       } else if (type == LUA_TSTRING) {
+               if (lua_isstring(L, index))
+                       return true;
+       }
+
+       // Types mismatch. Log unique line.
+       std::string backtrace = std::string("Invalid field ") + fieldname +
+               " (expected " + lua_typename(L, type) +
+               " got " + lua_typename(L, t) + ").\n" + script_get_backtrace(L);
+
+       u64 hash = murmur_hash_64_ua(backtrace.data(), backtrace.length(), 0xBADBABE);
+       if (warned_msgs.find(hash) == warned_msgs.end()) {
+               errorstream << backtrace << std::endl;
+               warned_msgs.insert(hash);
+       }
+
+       return false;
 }
 
 bool getstringfield(lua_State *L, int table,