Re: [PATCH 02/19] diff: move line ending check into emit_hunk_header
From: Junio C Hamano <hidden>
Date: 2017-05-15 06:48:32
Stefan Beller [off-list ref] writes:
In a later patch, I want to propose an option to detect&color moved lines in a diff, which cannot be done in a one-pass over the diff. Instead we need to go over the whole diff twice, because we cannot detect the first line of the two corresponding lines (+ and -) that got moved. So to prepare the diff machinery for two pass algorithms (i.e. buffer it all up and then operate on the result), move all emissions to places, such that the only emitting function is emit_line_0. This patch moves code that is conceptually part of emit_hunk_header, but was using output in fn_out_consume, back to emit_hunk_header.
Makes sort-of sense. If I were selling this patch, I'd remove the first two paragraph and stress on how completing the line inside emit_hunk_header() is conceptually cleaner than doing it outside. emit_hunk_header() function is responsible for assembling a hunk header and calling emit_line() to send the hunk header to the output file. Its only caller fn_out_consume() needs to prepare for a case where the function emits an incomplete line and add the terminating LF. Instead make sure emit_hunk_header() to always send a completed line to emit_line(). or something like that. Note that I am not saying "buffering the entire diff in-core? why should we support such a use case?". I am saying that this change is a clean-up that is justifiable, without having to answer such a question.
quoted hunk
Meanwhile simplify it by using a function that is designed for it. Signed-off-by: Stefan Beller <redacted> --- diff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/diff.c b/diff.c index 3f5bf8b5a4..c2ed605cd0 100644 --- a/diff.c +++ b/diff.c@@ -677,6 +677,8 @@ static void emit_hunk_header(struct emit_callback *ecbdata, } strbuf_add(&msgbuf, line + len, org_len - len); + strbuf_complete_line(&msgbuf); + emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len); strbuf_release(&msgbuf); }@@ -1315,8 +1317,6 @@ static void fn_out_consume(void *priv, char *line, unsigned long len) len = sane_truncate_line(ecbdata, line, len); find_lno(line, ecbdata); emit_hunk_header(ecbdata, line, len); - if (line[len-1] != '\n') - putc('\n', o->file); return; }