Fix NodeDef backwards compatibility to 5.3.0 (#11942)

1. Fixes crashes on older clients when [png is used as base image
2. Fixes liquid type assertion fails on debug builds

diff --git a/src/nodedef.cpp b/src/nodedef.cpp
index 6f52b608b48bc4e6ba254a5ad4f947566f184447..8a55428371236067fa7999875f9f8e106cb65afa 100644 (file)
--- a/src/nodedef.cpp
+++ b/src/nodedef.cpp
@@ -207,7 +207,17 @@ void TileDef::serialize(std::ostream &os, u16 protocol_version) const
        u8 version = 6;
        writeU8(os, version);
 
-       os << serializeString16(name);
+       if (protocol_version > 39) {
+               os << serializeString16(name);
+       } else {
+               // Before f018737, TextureSource::getTextureAverageColor did not handle
+               // missing textures. "[png" can be used as base texture, but is not known
+               // on older clients. Hence use "blank.png" to avoid this problem.
+               if (!name.empty() && name[0] == '[')
+                       os << serializeString16("blank.png^" + name);
+               else
+                       os << serializeString16(name);
+       }
        animation.serialize(os, version);
        bool has_scale = scale > 0;
        u16 flags = 0;
@@ -491,7 +501,16 @@ void ContentFeatures::serialize(std::ostream &os, u16 protocol_version) const
        writeU32(os, damage_per_second);
 
        // liquid
-       writeU8(os, liquid_type);
+       LiquidType liquid_type_bc = liquid_type;
+       if (protocol_version <= 39) {
+               // Since commit 7f25823, liquid drawtypes can be used even with LIQUID_NONE
+               // solution: force liquid type accordingly to accepted values
+               if (drawtype == NDT_LIQUID)
+                       liquid_type_bc = LIQUID_SOURCE;
+               else if (drawtype == NDT_FLOWINGLIQUID)
+                       liquid_type_bc = LIQUID_FLOWING;
+       }
+       writeU8(os, liquid_type_bc);
        os << serializeString16(liquid_alternative_flowing);
        os << serializeString16(liquid_alternative_source);
        writeU8(os, liquid_viscosity);