Warn about non-portable use of unescaped backslash at end of string,

and treat it as if it were escaped.
* src/tr.c (unquote): Considering that such usage would make GNU tr
from coreutils-5.2.1 and earlier *fail*, the least we can do now is
to warn about it.  Solaris' tr ignores it.
* NEWS: Mention this.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/tr.c b/src/tr.c
index 28eeac35a..871542a27 100644
--- a/src/tr.c
+++ b/src/tr.c
@@ -525,8 +525,9 @@ unquote (char const *s, struct E_string *es)
 		}
 	      break;
 	    case '\0':
-	      /* POSIX seems to require that a trailing backslash must
-		 stand for itself.  Weird.  */
+	      error (0, 0, _("warning: an unescaped backslash "
+			     "at end of string is not portable"));
+	      /* POSIX is not clear about this.  */
 	      es->escaped[j] = false;
 	      i--;
 	      c = '\\';