Re: [PATCH v4 1/2] merge-file: let conflict markers match end-of-line style of the context

Johannes Schindelin [off-list ref] writes:

+static int is_cr_needed(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m)
+{
+	int needs_cr;
+
+	/* Match post-images' preceding, or first, lines' end-of-line style */
+	needs_cr = is_eol_crlf(&xe1->xdf2, m->i1 ? m->i1 - 1 : 0);
+	if (needs_cr)
+		needs_cr = is_eol_crlf(&xe2->xdf2, m->i2 ? m->i2 - 1 : 0);
+	/* Look at pre-image's first line, unless we already settled on LF */
+	if (needs_cr)
+		needs_cr = is_eol_crlf(&xe1->xdf1, 0);
+	/* If still undecided, use LF-only */
+	return needs_cr < 0 ? 0 : needs_cr;
+}

Retrying with other images when needs_cr is either -1 (unknown) or 1
(known to be true) was tricky; I had to read it twice and think
about it for 30 seconds before convincing myself that the code does
what the log message specifies it should.

That is probably because I was thinking in terms of "do we know that
we need to add a CR?"; if I read "needs_cr" in my head as "we might
want to add a CR", everything becomes much more clear, but perhaps
it is just me.

The return value of this function is definitely "do we need and want
to add a CR", and it is appropriately named.

Thanks.