From e5e73ff20b5a750b9622438fd877f4e4a4c3519b Mon Sep 17 00:00:00 2001 From: Jeff King Date: Thu, 4 Dec 2014 20:28:54 -0500 Subject: for_each_reflog_ent_reverse: fix newlines on block boundaries When we read a reflog file in reverse, we read whole chunks of BUFSIZ bytes, then loop over the buffer, parsing any lines we find. We find the beginning of each line by looking for the newline from the previous line. If we don't find one, we know that we are either at the beginning of the file, or that we have to read another block. In the latter case, we stuff away what we have into a strbuf, read another block, and continue our parse. But we missed one case here. If we did find a newline, and it is at the beginning of the block, we must also stuff that newline into the strbuf, as it belongs to the block we are about to read. The minimal fix here would be to add this special case to the conditional that checks whether we found a newline. But we can make the flow a little clearer by rearranging a bit: we first handle lines that we are going to show, and then at the end of each loop, stuff away any leftovers if necessary. That lets us fold this special-case in with the more common "we ended in the middle of a line" case. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- refs.c | 47 ++++++++++++++++++++++++++++++++++++----------- 1 file changed, 36 insertions(+), 11 deletions(-) (limited to 'refs.c') diff --git a/refs.c b/refs.c index 5e5a3824b9..8ed9aee939 100644 --- a/refs.c +++ b/refs.c @@ -3089,24 +3089,49 @@ int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void bp = find_beginning_of_line(buf, scanp); - if (*bp != '\n') { - strbuf_splice(&sb, 0, 0, buf, endp - buf); - if (pos) - break; /* need to fill another block */ - scanp = buf - 1; /* leave loop */ - } else { + if (*bp == '\n') { /* - * (bp + 1) thru endp is the beginning of the - * current line we have in sb + * The newline is the end of the previous line, + * so we know we have complete line starting + * at (bp + 1). Prefix it onto any prior data + * we collected for the line and process it. */ strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1)); scanp = bp; endp = bp + 1; + ret = show_one_reflog_ent(&sb, fn, cb_data); + strbuf_reset(&sb); + if (ret) + break; + } else if (!pos) { + /* + * We are at the start of the buffer, and the + * start of the file; there is no previous + * line, and we have everything for this one. + * Process it, and we can end the loop. + */ + strbuf_splice(&sb, 0, 0, buf, endp - buf); + ret = show_one_reflog_ent(&sb, fn, cb_data); + strbuf_reset(&sb); + break; } - ret = show_one_reflog_ent(&sb, fn, cb_data); - strbuf_reset(&sb); - if (ret) + + if (bp == buf) { + /* + * We are at the start of the buffer, and there + * is more file to read backwards. Which means + * we are in the middle of a line. Note that we + * may get here even if *bp was a newline; that + * just means we are at the exact end of the + * previous line, rather than some spot in the + * middle. + * + * Save away what we have to be combined with + * the data from the next read. + */ + strbuf_splice(&sb, 0, 0, buf, endp - buf); break; + } } } -- cgit v1.2.3