From ef953bdb67b15c7c20142b2209579e146700964c Mon Sep 17 00:00:00 2001
From: Marco Comini <marco.comini@uniud.it>
Date: Tue, 17 Mar 2026 10:50:04 +0100
Subject: [PATCH] ISSUE 352: Fix extra initial LR(0) seed in genLR0items

---
 lib/tabular/src/Happy/Tabular/LALR.lhs |  2 +-
 tests/Makefile                         |  2 +-
 tests/issue352.y                       | 23 +++++++++++++++++++++++
 3 files changed, 25 insertions(+), 2 deletions(-)
 create mode 100644 tests/issue352.y

diff --git a/lib/tabular/src/Happy/Tabular/LALR.lhs b/lib/tabular/src/Happy/Tabular/LALR.lhs
index 2c109ca0..6ff7d8ea 100644
--- a/lib/tabular/src/Happy/Tabular/LALR.lhs
+++ b/lib/tabular/src/Happy/Tabular/LALR.lhs
@@ -237,7 +237,7 @@ information about which sets were generated by which others.
 
 >    n_starts = length (starts g)
 >    startRules :: [Set Lr0Item]
->    startRules = [ Set.singleton (Lr0 rule 0) | rule <- [0..n_starts] ]
+>    startRules = [ Set.singleton (Lr0 rule 0) | rule <- [0..n_starts-1] ]
 
 >    tokens = non_terminals g ++ terminals g
 
diff --git a/tests/Makefile b/tests/Makefile
index 056e129b..8e7d2c8a 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -39,7 +39,7 @@ TESTS = Test.ly TestMulti.ly TestPrecedence.ly bug001.ly \
 	typeclass_monad001.y typeclass_monad002.ly typeclass_monad_lexer.y \
 	rank2.y shift01.y \
 	AttrGrammar001.y AttrGrammar002.y \
-	Pragma.y
+	Pragma.y issue352.y
 
 ERROR_TESTS = error001.y issue335.y
 
diff --git a/tests/issue352.y b/tests/issue352.y
new file mode 100644
index 00000000..08cbc3b0
--- /dev/null
+++ b/tests/issue352.y
@@ -0,0 +1,23 @@
+{
+module Issue352 where
+}
+%name parseS S
+%tokentype { Token }
+%token
+  a       { A }
+  w       { W }
+  useless { U }
+
+%%
+
+UseLess : useless UseLess  { () }
+        | useless          { () }
+
+S : a w  { () }
+
+{
+data Token = A | W | U
+
+happyError :: [Token] -> a
+happyError _ = error "err"
+}