src: do not make Resize(0)’d buffers base nullptr

addaleax · BridgeAR · commit d117e41e5066 · 2019-03-22T00:47:15.000+01:00
This fixes issues in which APIs that accept pointers created this way treat `nullptr` and a zero-length buffer differently. We already do something similar for our `Malloc()` implementation. PR-URL: #26731 Fixes: #26514 Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Richard Lau <riclau@uk.ibm.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
diff --git a/src/env-inl.h b/src/env-inl.h
@@ -759,8 +759,10 @@ inline AllocatedBuffer::AllocatedBuffer(Environment* env, uv_buf_t buf)
     : env_(env), buffer_(buf) {}
 
 inline void AllocatedBuffer::Resize(size_t len) {
-  char* new_data = env_->Reallocate(buffer_.base, buffer_.len, len);
-  CHECK_IMPLIES(len > 0, new_data != nullptr);
+  // The `len` check is to make sure we don't end up with `nullptr` as our base.
+  char* new_data = env_->Reallocate(buffer_.base, buffer_.len,
+                                    len > 0 ? len : 1);
+  CHECK_NOT_NULL(new_data);
   buffer_ = uv_buf_init(new_data, len);
 }
 
