crecord: avoid duplicating lines when reverting noeol->eol change...
crecord: avoid duplicating lines when reverting noeol->eol change
When reversing a patch that looks like this while using crecord:
```
@@ -301,4 +302,4 @@ zza
zzb
zzc
zzd
-zze
\ No newline at end of file
+zze
```
we would previously reverse the `-zze` line to be an add, encounter the "no
newline" line and stop inspecting lines. This caused us to duplicate the line,
producing `zzezze` (still without a newline).
`break` is the correct action if we know there will be no lines afterwards, as
would be the case in an eol -> noeol transition. It is incorrect if there are
lines afterward, such as if both sides are missing the newline or if only the
lhs is missing the newline.
Differential Revision:
https://phab.mercurial-scm.org/D12441