Send Unicode directional isolate characters around horizontal pane

borders if the terminal support UTF-8 and an extension terminfo(5)
capability "Bidi" is present. On terminals with BiDi support (ie, VTE)
this seems to be enough to display right-to-left text acceptably enough
to be usable (with some caveats about the mouse position). Requested by
and with help from Mahmoud Elagdar in GitHub issue 2425.

1 files changed, 2 insertions, 2 deletions

diff --git a/grid.c b/grid.c
index cce304c9..7744587a 100644
--- a/grid.c
+++ b/grid.c
@@ -1045,14 +1045,14 @@ grid_duplicate_lines(struct grid *dst, u_int dy, struct grid *src, u_int sy,
 			    srcl->cellsize * sizeof *dstl->celldata);
 		} else
 			dstl->celldata = NULL;
-
 		if (srcl->extdsize != 0) {
 			dstl->extdsize = srcl->extdsize;
 			dstl->extddata = xreallocarray(NULL, dstl->extdsize,
 			    sizeof *dstl->extddata);
 			memcpy(dstl->extddata, srcl->extddata, dstl->extdsize *
 			    sizeof *dstl->extddata);
-		}
+		} else
+			dstl->extddata = NULL;
 
 		sy++;
 		dy++;