diff --git a/convert.c b/convert.c index c028275c14..8daf4e48e5 100644 --- a/convert.c +++ b/convert.c @@ -879,7 +879,8 @@ int is_null_stream_filter(struct stream_filter *filter) struct lf_to_crlf_filter { struct stream_filter filter; - unsigned want_lf:1; + unsigned has_held:1; + char held; }; static int lf_to_crlf_filter_fn(struct stream_filter *filter, @@ -889,10 +890,14 @@ static int lf_to_crlf_filter_fn(struct stream_filter *filter, size_t count, o = 0; struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter; - /* Output a pending LF if we need to */ - if (lf_to_crlf->want_lf) { - output[o++] = '\n'; - lf_to_crlf->want_lf = 0; + /* + * We may be holding onto the CR to see if it is followed by a + * LF, in which case we would need to go to the main loop. + * Otherwise, just emit it to the output stream. + */ + if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) { + output[o++] = lf_to_crlf->held; + lf_to_crlf->has_held = 0; } /* We are told to drain */ @@ -902,22 +907,57 @@ static int lf_to_crlf_filter_fn(struct stream_filter *filter, } count = *isize_p; - if (count) { + if (count || lf_to_crlf->has_held) { size_t i; + int was_cr = 0; + + if (lf_to_crlf->has_held) { + was_cr = 1; + lf_to_crlf->has_held = 0; + } + for (i = 0; o < *osize_p && i < count; i++) { char ch = input[i]; + if (ch == '\n') { output[o++] = '\r'; - if (o >= *osize_p) { - lf_to_crlf->want_lf = 1; - continue; /* We need to increase i */ - } + } else if (was_cr) { + /* + * Previous round saw CR and it is not followed + * by a LF; emit the CR before processing the + * current character. + */ + output[o++] = '\r'; } + + /* + * We may have consumed the last output slot, + * in which case we need to break out of this + * loop; hold the current character before + * returning. + */ + if (*osize_p <= o) { + lf_to_crlf->has_held = 1; + lf_to_crlf->held = ch; + continue; /* break but increment i */ + } + + if (ch == '\r') { + was_cr = 1; + continue; + } + + was_cr = 0; output[o++] = ch; } *osize_p -= o; *isize_p -= i; + + if (!lf_to_crlf->has_held && was_cr) { + lf_to_crlf->has_held = 1; + lf_to_crlf->held = '\r'; + } } return 0; }