lua: proper early-return via guard+raise sentinel; fixes if-then-return-end-rest +3 tests

lib/lua/test.sh

@@ -936,6 +936,14 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 1842)
 (eval "(lua-eval-ast \"if -2^2 == -4 then return 1 else return 0 end\")")
 
+;; ── Early-return inside nested block (guard+raise sentinel) ──
+(epoch 1850)
+(eval "(lua-eval-ast \"local function f(n) if n < 0 then return -1 end return n * 2 end return f(-5)\")")
+(epoch 1851)
+(eval "(lua-eval-ast \"local function f(n) if n < 0 then return -1 end return n * 2 end return f(7)\")")
+(epoch 1852)
+(eval "(lua-eval-ast \"function f(i) if type(i) ~= \\\"number\\\" then return i, \\\"jojo\\\" end if i > 0 then return i, f(i-1) end end local a, b = f(3) return a\")")
+
 EPOCHS
 
 OUTPUT=$(timeout 60 "$SX_SERVER" < "$TMPFILE" 2>/dev/null)
@@ -1414,6 +1422,11 @@ check 1840 "-2^2 = -4"                      '-4'
 check 1841 "2^3^2 = 512 (right-assoc)"      '512'
 check 1842 "-2^2 == -4 true"                '1'
 
+# ── Early-return inside nested block ─────────────────────────
+check 1850 "early return negative path"     '-1'
+check 1851 "non-early return path"          '14'
+check 1852 "nested early-return recursion"  '3'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "ok $PASS/$TOTAL Lua-on-SX tests passed"