From 598253eac8f8dc93eaa1b19881db52cbfaf56819 Mon Sep 17 00:00:00 2001
From: Ingo Paschke <ipaschke@lpclabs.de>
Date: Mon, 25 May 2026 21:37:34 +0200
Subject: [PATCH] glyphs: rotate-5 in glyph_hash eliminates true collisions

The previous rotate-1-xor put consecutive characters' bits in
adjacent positions, so short similar names like fox/bat or
jaguar/lichen collided -- 164 colliding buckets across the 9577
named glyphs.  Rotate-5 spreads each character across a 5-bit
window: zero true collisions, one m68k ROL.L, no multiplication.

The 16 remaining same-hash buckets are name duplicates from a
separate compose_glyph_name bug, addressed by its own fix.
---
 src/glyphs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/glyphs.c b/src/glyphs.c
index 837190caf..1d57a4e78 100644
--- a/src/glyphs.c
+++ b/src/glyphs.c
@@ -618,7 +618,7 @@ glyph_hash(const char *id)
         if ('A' <= ch && ch <= 'Z') {
             ch += 'a' - 'A';
         }
-        hash = (hash << 1) | (hash >> 31);
+        hash = (hash << 5) | (hash >> 27);
         hash ^= ch;
     }
     return hash;