Re: Problem with diff

On Tue, 18 Oct 2011 08:55:44 +0000, Daniel Shahaf wrote:
> >
> > as the diff.
> >
> > But happens only with this specific file; can't reproduce with
> > other content.
> >
>
> Does the file (either before or after the append) contain two identical
> lines? If so, could you try replacing each line in the file by a unique
> string? You can do that with
>
> % perl -lne 'print $h{$_} ||= $unique++' \
> <kadr.polon.p >kadr.polon.p.anonymized

Nice trick, but unnecessary. The original file was an attachment on the
mail I replied to.

But that does not trigger the bug:

===================================================================
--- kadr.polon.p (revision 1)
+++ kadr.polon.p (revision 2)
@@ -450,3 +450,5 @@
 369
 370
 371
+
+/**/

Passing the file through rot13: Bug stays:

===================================================================
--- kadr.polon.p (revision 1)
+++ kadr.polon.p (revision 2)
@@ -461,6 +461,8 @@
    RZCGL GRZC-GNOYR gg_glganhx.
    RZCGL GRZC-GNOYR gg_fganhx.
    cBfgngav = iVybfp.
+ VS iVybfp = (cFgneg + cVybfp - 1) gura yrnir Tybony_ybbc.
+RAQ.
    VS iVybfp = (cFgneg + cVybfp - 1) gura yrnir Tybony_ybbc.
 RAQ.
 {jf_v/ybt.v}

Replacing each char by another one (individually, not caesar).
But stays, though no duplicate lines:

===================================================================
--- kadr.polon.p (revision 1)
+++ kadr.polon.p (revision 2)
@@ -461,6 +461,8 @@
    TVJBN TKFW-NXNXO kr_sqeujxy.
    KUNPS UABP-ASKTF rj_lgdujj.
    aOxxrupn = tMjwdl.
+ IA dOjubh = (hZnfpq + wPykty - 1) flse cbfgj Onaorw_svvq.
+AKM.
    IA dOjubh = (hZnfpq + wPykty - 1) flse cbfgj Onaorw_svvq.
 AKM.
 {iv_c/dpv.r}

Using cat -n on the file: Bug stays, even more surprisingly:

===================================================================
--- kadr.polon.p (revision 1)
+++ kadr.polon.p (revision 2)
@@ -461,6 +461,8 @@
    447 EMPTY TEMP-TABLE tt_tytnauk.
    448 EMPTY TEMP-TABLE tt_stnauk.
    449 pOstatni = vIlosc.
+ 450 IF vIlosc = (pStart + pIlosc - 1) then leave Global_loop.
+ 451 END.
    450 IF vIlosc = (pStart + pIlosc - 1) then leave Global_loop.
    451 END.
    452 {ws_i/log.i}

So, it is not the line uniqeness, but rather it looks like having to do
with the line length structure.

I really like to see *that* patch.

Andreas

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds <torvalds@*.org>
Date: Fri, 22 Jan 2010 07:29:21 -0800