Re: [PATCH v5 12/16] merge-recursive: flush output buffer before printing error messages

Johannes Schindelin [off-list ref] writes:

The data structure passed to the recursive merge machinery has a feature
where the caller can ask for the output to be buffered into a strbuf, by
setting the field 'buffer_output'.

Previously, we simply swallowed the buffered output when showing error
messages. With this patch, we show the output first, and only then print
the error message.

I didn't quite understand this paragraph until I realized that you
meant "when showing die message".  We died without flushing, losing
accumulated output.

+static int err(struct merge_options *o, const char *err, ...)
+{
+	va_list params;
+
+	va_start(params, err);
+	flush_output(o);

I would have written the above two swapped; va_start() logically
is about what happens in the next four lines.

+	strbuf_vaddf(&o->obuf, err, params);
+	error("%s", o->obuf.buf);
+	strbuf_reset(&o->obuf);

Sneaky ;-)

The remainder replaces error(...) with err(o, ...) and updates the
callchain to pass the merge_options around, which looked good.

Thanks.