diff options
| -rw-r--r-- | src/newgrf.cpp | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/src/newgrf.cpp b/src/newgrf.cpp index ee8e35526..55f64f461 100644 --- a/src/newgrf.cpp +++ b/src/newgrf.cpp @@ -3094,11 +3094,18 @@ static void CfgApply(byte *buf, int len) grfmsg(8, "CfgApply: Applying %u bytes from parameter 0x%02X at offset 0x%04X", param_size, param_num, offset); + bool carry = false; for (i = 0; i < param_size; i++) { uint32 value = GetParamVal(param_num + i / 4, NULL); + /* Reset carry flag for each iteration of the variable (only really + * matters if param_size is greater than 4) */ + if (i == 0) carry = false; if (add_value) { - _preload_sprite[offset + i] += GB(value, (i % 4) * 8, 8); + uint new_value = _preload_sprite[offset + i] + GB(value, (i % 4) * 8, 8) + (carry ? 1 : 0); + _preload_sprite[offset + i] = GB(new_value, 0, 8); + /* Check if the addition overflowed */ + carry = new_value >= 256; } else { _preload_sprite[offset + i] = GB(value, (i % 4) * 8, 8); } |