HTTP API: Allow binary downloads and headers (#8573)

Add minetest.features.httpfetch_binary_data

builtin/game/features.lua

@@ -12,6 +12,7 @@ core.features = {
 	no_chat_message_prediction = true,
 	object_use_texture_alpha = true,
 	object_independent_selectionbox = true,
+	httpfetch_binary_data = true,
 }
 
 function core.has_feature(arg)

doc/lua_api.txt

@@ -3527,11 +3527,14 @@ Utilities
           -- Chat messages are no longer predicted (0.4.16)
           no_chat_message_prediction = true,
           -- The transparency channel of textures can optionally be used on
-          -- objects (ie: players and lua entities) (5.0)
+          -- objects (ie: players and lua entities) (5.0.0)
           object_use_texture_alpha = true,
           -- Object selectionbox is settable independently from collisionbox
-          -- (5.0)
+          -- (5.0.0)
           object_independent_selectionbox = true,
+          -- Specifies whether binary data can be uploaded or downloaded using
+          -- the HTTP API (5.1.0)
+          httpfetch_binary_data = true,
       }
 
 * `minetest.has_feature(arg)`: returns `boolean, missing_features`

src/script/common/c_converter.cpp

@@ -540,9 +540,9 @@ v3s16 getv3s16field_default(lua_State *L, int table,
 }
 
 void setstringfield(lua_State *L, int table,
-		const char *fieldname, const char *value)
+		const char *fieldname, const std::string &value)
 {
-	lua_pushstring(L, value);
+	lua_pushlstring(L, value.c_str(), value.length());
 	if(table < 0)
 		table -= 1;
 	lua_setfield(L, table, fieldname);

src/script/common/c_converter.h

@@ -91,7 +91,7 @@ std::string        checkstringfield(lua_State *L, int table,
                              const char *fieldname);
 
 void               setstringfield(lua_State *L, int table,
-                             const char *fieldname, const char *value);
+                             const char *fieldname, const std::string &value);
 void               setintfield(lua_State *L, int table,
                              const char *fieldname, int value);
 void               setfloatfield(lua_State *L, int table,

src/script/common/helper.cpp

@@ -107,9 +107,10 @@ template <> v2f LuaHelper::readParam(lua_State *L, int index)
 
 template <> std::string LuaHelper::readParam(lua_State *L, int index)
 {
+	size_t length;
 	std::string result;
-	const char *str = luaL_checkstring(L, index);
-	result.append(str);
+	const char *str = luaL_checklstring(L, index, &length);
+	result.assign(str, length);
 	return result;
 }
 

src/script/lua_api/l_http.cpp

@@ -53,9 +53,8 @@ void ModApiHttp::read_http_fetch_request(lua_State *L, HTTPFetchRequest &req)
 	lua_getfield(L, 1, "post_data");
 	if (lua_istable(L, 2)) {
 		lua_pushnil(L);
-		while (lua_next(L, 2) != 0)
-		{
-			req.post_fields[luaL_checkstring(L, -2)] = luaL_checkstring(L, -1);
+		while (lua_next(L, 2) != 0) {
+			req.post_fields[readParam<std::string>(L, -2)] = readParam<std::string>(L, -1);
 			lua_pop(L, 1);
 		}
 	} else if (lua_isstring(L, 2)) {
@@ -66,10 +65,8 @@ void ModApiHttp::read_http_fetch_request(lua_State *L, HTTPFetchRequest &req)
 	lua_getfield(L, 1, "extra_headers");
 	if (lua_istable(L, 2)) {
 		lua_pushnil(L);
-		while (lua_next(L, 2) != 0)
-		{
-			const char *header = luaL_checkstring(L, -1);
-			req.extra_headers.emplace_back(header);
+		while (lua_next(L, 2) != 0) {
+			req.extra_headers.emplace_back(readParam<std::string>(L, -1));
 			lua_pop(L, 1);
 		}
 	}
@@ -83,7 +80,7 @@ void ModApiHttp::push_http_fetch_result(lua_State *L, HTTPFetchResult &res, bool
 	setboolfield(L, -1, "timeout", res.timeout);
 	setboolfield(L, -1, "completed", completed);
 	setintfield(L, -1, "code", res.response_code);
-	setstringfield(L, -1, "data", res.data.c_str());
+	setstringfield(L, -1, "data", res.data);
 }
 
 // http_api.fetch_async(HTTPRequest definition)