From 9b440f279e05131db5d2bba15efcd6fcf930e5ed Mon Sep 17 00:00:00 2001
From: tour <yl_tour@posteo.de>
Date: Sat, 14 Sep 2024 20:42:42 +0200
Subject: [PATCH] fix edge case when lua keywords are used as keys

---
 alg1.lua    | 27 ++++++++++++++++++++++++++-
 alg2.lua    | 34 ++++++++++++++++++++++++++++++----
 algtour.lua | 27 ++++++++++++++++++++++++++-
 init.lua    |  3 ++-
 4 files changed, 84 insertions(+), 7 deletions(-)

diff --git a/alg1.lua b/alg1.lua
index dfe50bc..e67b6ef 100644
--- a/alg1.lua
+++ b/alg1.lua
@@ -44,11 +44,36 @@ local function stringToTable(str)
         end
     end
 
+    local lua_keywords = {
+        ["and"] = true,
+        ["break"] = true,
+        ["do"] = true,
+        ["else"] = true,
+        ["elseif"] = true,
+        ["end"] = true,
+        ["false"] = true,
+        ["for"] = true,
+        ["function"] = true,
+        ["goto"] = true,
+        ["if"] = true,
+        ["in"] = true,
+        ["local"] = true,
+        ["nil"] = true,
+        ["not"] = true,
+        ["or"] = true,
+        ["repeat"] = true,
+        ["return"] = true,
+        ["then"] = true,
+        ["true"] = true,
+        ["until"] = true,
+        ["while"] = true,
+    }
+
     local function parseKey(s, i)
         s = s:match("^%s*(.-)%s*$", i) -- Trim leading/trailing spaces
         if s:find("^[%a_]") then
             local key = s:match("^[%a%d_]*")
-            if key ~= "true" and key ~= "false" and key ~= "nil" then
+            if not lua_keywords[key] then
                 return key, #key
             end
         end
diff --git a/alg2.lua b/alg2.lua
index 2b358ab..ccbcfae 100644
--- a/alg2.lua
+++ b/alg2.lua
@@ -41,15 +41,41 @@ local function codedStringToTable(str)
         end
     end
 
+    local lua_keywords = {
+        ["and"] = true,
+        ["break"] = true,
+        ["do"] = true,
+        ["else"] = true,
+        ["elseif"] = true,
+        ["end"] = true,
+        ["false"] = true,
+        ["for"] = true,
+        ["function"] = true,
+        ["goto"] = true,
+        ["if"] = true,
+        ["in"] = true,
+        ["local"] = true,
+        ["nil"] = true,
+        ["not"] = true,
+        ["or"] = true,
+        ["repeat"] = true,
+        ["return"] = true,
+        ["then"] = true,
+        ["true"] = true,
+        ["until"] = true,
+        ["while"] = true,
+    }
+
     local function parseKey(s)
         s = s:match("^%s*(.-)%s*$") -- trim whitespace
         if s:match("^%[(.*)%]$") then
             return parseValue(s:match("^%[(.*)%]$"))
-        elseif s:find("^[%a_][%a%d_]*$") then -- make sure the string is a valid lua identifier
-            return s
-        else
-            error("Unrecognized key: " .. s)
         end
+        s = s:match("^[%a_][%a%d_]*$")  -- make sure the string is a valid lua identifier
+        if s and not lua_keywords[s] then
+            return s
+        end
+        error("Unrecognized key: " .. s)
     end
 
     local tbl = {}
diff --git a/algtour.lua b/algtour.lua
index 1091300..2c8e4ee 100644
--- a/algtour.lua
+++ b/algtour.lua
@@ -38,6 +38,31 @@ local function parse_value(str)
     return false, string.format("unable to parse '%s'", str)
 end
 
+local lua_keywords = {
+    ["and"] = true,
+    ["break"] = true,
+    ["do"] = true,
+    ["else"] = true,
+    ["elseif"] = true,
+    ["end"] = true,
+    ["false"] = true,
+    ["for"] = true,
+    ["function"] = true,
+    ["goto"] = true,
+    ["if"] = true,
+    ["in"] = true,
+    ["local"] = true,
+    ["nil"] = true,
+    ["not"] = true,
+    ["or"] = true,
+    ["repeat"] = true,
+    ["return"] = true,
+    ["then"] = true,
+    ["true"] = true,
+    ["until"] = true,
+    ["while"] = true,
+}
+
 local function parse_key(str)
     if str:find("^%[.*%]$") then
         -- if in brackets, we can threat it like a value
@@ -51,7 +76,7 @@ local function parse_key(str)
         return true, key
     end
     -- make sure the key is a valid identifier
-    if str:find("^[%a_][%a%d_]*$") then
+    if str:find("^[%a_][%a%d_]*$") and not lua_keywords[str] then
         return true, str
     end
     return false, string.format("'%s' is not a valid key", str)
diff --git a/init.lua b/init.lua
index aeb69b4..7f5e51f 100644
--- a/init.lua
+++ b/init.lua
@@ -26,6 +26,7 @@ local tests = {
     "{a = 1",
     "{'unclosed string\\'}",
     "{invalid key = 3}",
+    "{false = 2}", -- invalid key
     "{1 = 2}", -- invalid key
     "{,}",
     "{[nil] = 1}"
@@ -44,7 +45,7 @@ local function test(alg)
     end
     local t2 = minetest.get_us_time()
     minetest.log("action",alg .. " = " .. (t2-t1))
-    print(dump(outcome))
+    -- print(dump(outcome))
 end
 
 test("s2t1")