Hi Thomas,


On Sun, 14 Apr 2019, Thomas Gummerer wrote:

When postprocessing the inner diff in range-diff, we currently replace
the whole hunk header line with just "@@".  This matches how 'git
tbdiff' used to handle hunk headers as well.

Most likely this is being done because line numbers in the hunk header
are not relevant without other changes.  They can for example easily
change if a range is rebased, and lines are added/removed before a
change that we actually care about in our ranges.

However it can still be useful to have the function name that 'git
diff' extracts as additional context for the change.

Note that it is not guaranteed that the hunk header actually shows up
in the range-diff, and this change only aims to improve the case where
a hunk header would already be included in the final output.

Makes sense.

Rather than using the magic constant "3", it would probably make sense to
declare `skip_lineno` outside of the `if` construct, and use
`skip_prefix(line.buf, "@@ ", &skip_lineno)` instead of
`starts_with(...)`.

We *will*, however, want to have a safeguard against `strstr()` not
finding anything. Maybe re-use the `p` variable that we already have, and
do this instead:

		} else if (skip_prefix(line.buf, "@@ ", &p) &&
			   (p = strstr(p, "@@"))) {

+			strbuf_remove(&line, 0, skip_lineno - line.buf);
+			strbuf_addch(&buf, ' ');

Shorter:

			strbuf_splice(&line, 0, p - line.buf, " ", 1);

(assuming that you accept my suggestion to use `p` instead of
`skip_lineno`...)

Thanks,
Dscho

+			strbuf_addbuf(&buf, &line);
+		} else if (!line.buf[0] || starts_with(line.buf, "index "))
 			/*
 			 * A completely blank (not ' \n', which is context)
 			 * line is not valid in a diff.  We skip it
--
2.21.0.593.g511ec345e1