Merge pull request #158 from benmanns/streaming-write-malloc-gc-corruption

Streaming write malloc gc corruption

Author: SpringMT

ext/zstdruby/streaming_compress.c

@@ -211,6 +211,8 @@ rb_streaming_compress_flush(VALUE obj)
   VALUE drained = no_compress(sc, ZSTD_e_flush);
   VALUE out = rb_str_dup(sc->pending);
   rb_str_cat(out, RSTRING_PTR(drained), RSTRING_LEN(drained));
+  /* prevent `drained` from being freed by GC inside rb_str_cat */
+  RB_GC_GUARD(drained);
   rb_str_resize(sc->pending, 0);
   return out;
 }
@@ -223,6 +225,8 @@ rb_streaming_compress_finish(VALUE obj)
   VALUE drained = no_compress(sc, ZSTD_e_end);
   VALUE out = rb_str_dup(sc->pending);
   rb_str_cat(out, RSTRING_PTR(drained), RSTRING_LEN(drained));
+  /* prevent `drained` from being freed by GC inside rb_str_cat */
+  RB_GC_GUARD(drained);
   rb_str_resize(sc->pending, 0);
   return out;
 }

ext/zstdruby/zstdruby.c

@@ -132,6 +132,7 @@ static VALUE rb_decompress(int argc, VALUE *argv, VALUE self)
         result = out;
       } else {
         rb_str_cat(result, RSTRING_PTR(out), RSTRING_LEN(out));
+        RB_GC_GUARD(out);
       }
 
       if (consumed == 0) {