httpfs: Strenghten code to avoid corruptions with servers sending mor…

…e data than asked

Fixes duckdb#8930 and duckdb#8908 (avoiding the fatal crash).

HTTP server are allowed to send back more data than asked for, and be somehow unreliably.
In this case a GET request with a range headers gets more data than asked for, and with very
big files we ended up overriding the current buffer.

This is an uncommon but legal behaviour, to properly handle this situation so we will have
to improve logic elsewhere to properly handle this case.

extension/httpfs/httpfs.cpp

@@ -329,6 +329,14 @@ unique_ptr<ResponseWrapper> HTTPFileSystem::GetRangeRequest(FileHandle &handle,
 				    hfs.state->total_bytes_received += data_length;
 			    }
 			    if (buffer_out != nullptr) {
+				    if (data_length + out_offset > buffer_out_len) {
+					    // As of v0.8.2-dev4424 we might end up here when very big files are served from servers
+					    // that returns more data than requested via range header. This is an uncommon but legal
+					    // behaviour, so we have to improve logic elsewhere to properly handle this case.
+
+					    // To avoid corruption of memory, we bail out.
+					    return false;
+				    }
 				    memcpy(buffer_out + out_offset, data, data_length);
 				    out_offset += data_length;
 			    }