Re: diff-sanity-check-hunk fails on "unterminated" hunks

[Stefan Monnier]

> to get all differing files at once (as any reasonable person would), I
> produced the diffs separately and concatenated them:

Yes, these diffs are problematic because you need to count the lines in
order to do the right thing and most of diff-mode.el doesn't count the lines
but just presumes that the hunk-end will be self-evident.

>    The second attachment
> (fix-diff-sanity-check-hunk-for-unterminated-hunk.patch) fixes the
> problem by doing the normal exit test (exit when both line counters get
> to zero) before checking the BOL character.  (It's actually just a small
> change but with a lot of whitespace adjustment.)

This might be right, but I think I prefer to also complain when the hunk is
formally correct but is followed by things that look like a continuation.
Especially since diff-mode will typically not handle them correctly.

Does the patch below address your particular problem (which I agree is
a case that should be handled, I've encountered it several times already,
tho that was before implementing diff-sanity-check-hunk, obviously).


        Stefan


--- diff-mode.el        27 aoû 2007 23:25:15 -0400      1.99.2.4
+++ diff-mode.el        12 sep 2007 01:03:59 -0400      
@@ -1181,7 +1181,16 @@
             (while
                 (case (char-after)
                   (?\s (decf before) (decf after) t)
-                  (?- (decf before) t)
+                  (?-
+                   (if (and (looking-at diff-file-header-re)
+                            (zerop before) (zerop after))
+                       ;; No need to query: this is a case where two patches
+                       ;; are concatenated and only counting the lines will
+                       ;; give the right result.  Let's just add an empty
+                       ;; line so that our code which doesn't count lines
+                       ;; will not get confused.
+                       (progn (save-excursion (insert "\n")) nil)
+                     (decf before) t))
                   (?+ (decf after) t)
                   (t
                    (cond