From 9ce3f8fb0821787fe97f23191ee5800ac5a6c587 Mon Sep 17 00:00:00 2001
From: Jaco <jacogr@gmail.com>
Date: Sun, 26 Nov 2023 14:07:54 +0200
Subject: [PATCH] Sync fflate huffman tree with upstream

---
 packages/wasm-util/src/fflate.ts | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/packages/wasm-util/src/fflate.ts b/packages/wasm-util/src/fflate.ts
index 9936c43e..e067b821 100644
--- a/packages/wasm-util/src/fflate.ts
+++ b/packages/wasm-util/src/fflate.ts
@@ -92,10 +92,12 @@ const hMap = ((cd: Uint8Array, mb: number, r: 0 | 1) => {
   // u16 "map": index -> # of codes with bit length = index
   const l = new u16(mb);
   // length of cd must be 288 (total # of codes)
-  for (; i < s; ++i) ++l[cd[i] - 1];
+  for (; i < s; ++i) {
+    if (cd[i]) ++l[cd[i] - 1];
+  }
   // u16 "map": index -> minimum code for bit length = index
   const le = new u16(mb);
-  for (i = 0; i < mb; ++i) {
+  for (i = 1; i < mb; ++i) {
     le[i] = (le[i - 1] + l[i - 1]) << 1;
   }
   let co: Uint16Array;
@@ -116,13 +118,17 @@ const hMap = ((cd: Uint8Array, mb: number, r: 0 | 1) => {
         // m is end value
         for (const m = v | ((1 << r) - 1); v <= m; ++v) {
           // every 16 bit value starting with the code yields the same result
-          co[rev[v] >>> rvb] = sv;
+          co[rev[v] >> rvb] = sv;
         }
       }
     }
   } else {
     co = new u16(s);
-    for (i = 0; i < s; ++i) co[i] = rev[le[cd[i] - 1]++] >>> (15 - cd[i]);
+    for (i = 0; i < s; ++i) {
+      if (cd[i]) {
+        co[i] = rev[le[cd[i] - 1]++] >> (15 - cd[i]);
+      }
+    }
   }
   return co;
 });