src: fix setting Converter sub char length

Signed-off-by: James M Snell <[email protected]> Fixes: #38330 PR-URL: #38331 Reviewed-By: Juan José Arboleda <[email protected]> Reviewed-By: Benjamin Gruenbaum <[email protected]>
nodejs · Apr 29, 2021 · 09cacd7 · 09cacd7
1 parent 3649ec5
commit 09cacd7
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Showing 2 changed files with 17 additions and 2 deletions.
diff --git a/src/node_i18n.cc b/src/node_i18n.cc
@@ -148,8 +148,13 @@ MaybeLocal<Object> Transcode(Environment* env,
   *status = U_ZERO_ERROR;
   MaybeLocal<Object> ret;
   MaybeStackBuffer<char> result;
-  Converter to(toEncoding, "?");
+  Converter to(toEncoding);
   Converter from(fromEncoding);
+
+  size_t sublen = ucnv_getMinCharSize(to.conv());
+  std::string sub(sublen, '?');
+  to.set_subst_chars(sub.c_str());
+
   const uint32_t limit = source_length * to.max_char_size();
   result.AllocateSufficientStorage(limit);
   char* target = *result;
@@ -190,7 +195,12 @@ MaybeLocal<Object> TranscodeFromUcs2(Environment* env,
   *status = U_ZERO_ERROR;
   MaybeStackBuffer<UChar> sourcebuf;
   MaybeLocal<Object> ret;
-  Converter to(toEncoding, "?");
+  Converter to(toEncoding);
+
+  size_t sublen = ucnv_getMinCharSize(to.conv());
+  std::string sub(sublen, '?');
+  to.set_subst_chars(sub.c_str());
+
   const size_t length_in_chars = source_length / sizeof(UChar);
   CopySourceBuffer(&sourcebuf, source, source_length, length_in_chars);
   MaybeStackBuffer<char> destbuf(length_in_chars);

diff --git a/test/parallel/test-icu-transcode.js b/test/parallel/test-icu-transcode.js
@@ -83,3 +83,8 @@ assert.deepStrictEqual(
   const dest = buffer.transcode(new Uint8Array(), 'utf8', 'latin1');
   assert.strictEqual(dest.length, 0);
 }
+
+// Test that it doesn't crash
+{
+  buffer.transcode(new buffer.SlowBuffer(1), 'utf16le', 'ucs2');
+}