diff: write prefix to the correct file

diff --git a/diff.c b/diff.c
index 732d4c227595873bb94224da618ce5612a7415af..951313467097e7283adcfd428bec78dc09b66b40 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -4483,7 +4483,7 @@ void diff_flush(struct diff_options *options)
                                struct strbuf *msg = NULL;
                                msg = options->output_prefix(options,
                                        options->output_prefix_data);
-                               fwrite(msg->buf, msg->len, 1, stdout);
+                               fwrite(msg->buf, msg->len, 1, options->file);
                        }
                        putc(options->line_termination, options->file);
                        if (options->stat_sep) {