Add test script for server error cases

Author: sfan5

.github/workflows/linux.yml

@@ -88,7 +88,7 @@ jobs:
       - name: Install deps
         run: |
           source ./util/ci/common.sh
-          install_linux_deps clang-7 llvm
+          install_linux_deps clang-7 llvm-7
 
       - name: Build
         run: |
@@ -102,6 +102,11 @@ jobs:
         run: |
           ./bin/minetest --run-unittests
 
+      # Do this here because we have ASan and error paths are sensitive to dangling pointers
+      - name: Test error cases
+        run: |
+          ./util/test_error_cases.sh
+
   # Current clang version
   clang_18:
     runs-on: ubuntu-24.04

util/helper_mod/error.lua

@@ -0,0 +1 @@
+error("intentional")

util/helper_mod/init.lua

@@ -48,4 +48,24 @@ elseif mode == "mapgen" then
 	end
 	core.after(0, next_, 1)
 
+elseif mode == "error" then
+
+	local n = tonumber(core.settings:get("error_type"))
+	local error_lua = core.get_modpath(core.get_current_modname()) .. "/error.lua"
+	if n == 1 then
+		print("=> error during startup <=")
+		error("intentional")
+	elseif n == 2 then
+		print("=> error on first step <=")
+		core.after(0, error, "intentional")
+	elseif n == 3 then
+		print("=> error in async script <=")
+		core.register_async_dofile(error_lua)
+	elseif n == 4 then
+		print("=> error in mapgen script <=")
+		core.register_mapgen_script(error_lua)
+	else
+		assert(false)
+	end
+
 end

util/test_error_cases.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+gameid=${gameid:-devtest}
+minetest=$dir/../bin/minetest
+testspath=$dir/../tests
+conf_server=$testspath/server.conf
+worldpath=$testspath/world
+
+[ -e "$minetest" ] || { echo "executable $minetest missing"; exit 1; }
+
+write_config () {
+	printf '%s\n' >"$conf_server" \
+		helper_mode=error mg_name=singlenode "$@"
+}
+
+run () {
+	timeout 10 "$@"
+	r=$?
+	echo "Exit status: $r"
+	[ $r -eq 124 ] && echo "(timed out)"
+	if [ $r -ne 1 ]; then
+		echo "-> Test failed"
+		exit 1
+	fi
+}
+
+rm -rf "$worldpath"
+mkdir -p "$worldpath/worldmods"
+
+ln -s "$dir/helper_mod" "$worldpath/worldmods/"
+
+args=(--server --config "$conf_server" --world "$worldpath" --gameid $gameid)
+
+# make sure we can tell apart sanitizer and minetest errors
+export ASAN_OPTIONS="exitcode=42"
+export MSAN_OPTIONS="exitcode=42"
+
+# see helper_mod/init.lua for the different types
+for n in $(seq 1 4); do
+	write_config error_type=$n
+	run "$minetest" "${args[@]}"
+	echo "---------------"
+done
+
+echo "All done."
+exit 0