"Phillip Wood via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > From: Phillip Wood <phillip.wood@xxxxxxxxxxxxx> > > When "add -p" parses diffs, it looks for context lines starting with a > single space. But when diff.suppressBlankEmpty is in effect, an empty > context line will omit the space, giving us a true empty line. This > confuses the parser, which is unable to split based on such a line. > > It's tempting to say that we should just make sure that we generate a > diff without that option. However, although we do not parse hunks that > the user has manually edited with parse_diff() we do allow the user > to split such hunks. As POSIX calls the decision of whether to print the > space here "implementation-defined" we need to handle edited hunks where > empty context lines omit the space. > > So let's handle both cases: a context line either starts with a space or > consists of a totally empty line by normalizing the first character to a > space when we parse them. Normalizing the first character rather than > changing the code to check for a space or newline will hopefully future > proof against introducing similar bugs if the code is changed. > > Reported-by: Ilya Tumaykin <itumaykin@xxxxxxxxx> > Helped-by: Jeff King <peff@xxxxxxxx> > Signed-off-by: Phillip Wood <phillip.wood@xxxxxxxxxxxxx> > --- Well written. Thanks for a pleasant read. > @@ -953,7 +960,7 @@ static int split_hunk(struct add_p_state *s, struct file_diff *file_diff, > context_line_count = 0; > > while (splittable_into > 1) { > - ch = s->plain.buf[current]; > + ch = normalize_marker(s->plain.buf + current); I wondered if &s->plain.buf[current] is easier to grok, but what's written already is good enough ;-) There is another explicit mention of ' ' in merge_hunks(). Unless we are normalizing the buffer here (which I do not think we do), wouldn't we have to make sure that the code over there also knows that an empty line in a patch is an unmodified empty line? if (plain[overlap_end] != ' ') return error(_("expected context line " "#%d in\n%.*s"),