Re: misleading diff-hunk header

On 08/24/12 11:44, Jeff King wrote:

With the old code, you'd get:

	diff --git a/old b/new
	index f384549..1066a25 100644
	--- a/old
	+++ b/new
	@@ -2,3 +2,3 @@ one
	 two
	-three
	+three -- modified
	 four

So the hunk header is showing you something useful; the element just
above your context. But with my patch, you'd see:

	diff --git a/old b/new
	index f384549..1066a25 100644
	--- a/old
	+++ b/new
	@@ -2,3 +2,3 @@ two
	 two
	-three
	+three -- modified
	 four

I.e., it shows the element just before the change, which is already in
the context anyway. So it's actually less useful. Although note that the
current behavior is not all that useful, either; it is not really giving
you any information about the change, but rather just showing one extra
line of context.

So I would say that which you would prefer might depend on exactly what
you are diffing. But I would also argue that in any case where the new
code produces a worse result, the hunk header was not all that useful to
begin with.

If the documented purpose of "diff -p" (and by proxy
diff.{type}.xfuncname) is to show the name of the *function*
containing the changed lines, and all you have is a list of lines
with no function names, it's pretty arbitrary to call either
behavior "worse". :-)

-tkc