The unalias argv array needs room for a trailing NULL.

NEWS.md

@@ -33,8 +33,6 @@ Protocol: 31 (unchanged)
 
  - Some rrsync fixes and enhancements to handle the latest options.
 
- - Fixed a crash in the `--iconv` code.
-
  - Fixed a problem with the `--link-dest`|`--copy-dest` code when `--xattrs`
    was specified along with multiple alternate-destination directories (it
    could possibly choose a bad file match while trying to find a better xattr
@@ -50,6 +48,10 @@ Protocol: 31 (unchanged)
  - Fixed a mismatch in the RSYNC_PID values when running both a `pre-xfer exec`
    and a `post-xfer exec`.
 
+ - Fixed a crash in the `--iconv` code.
+
+ - Fixed a rare crash in the popt_unalias() code.
+
 ### ENHANCEMENTS:
 
  - Various checksum enhancements, including the optional use of openssl's MD4 &

options.c

@@ -1287,10 +1287,11 @@ static void popt_unalias(poptContext con, const char *opt)
 {
 	struct poptAlias unalias;
 
+	memset(&unalias, 0, sizeof unalias);
+
 	unalias.longName = opt + 2; /* point past the leading "--" */
-	unalias.shortName = '\0';
 	unalias.argc = 1;
-	unalias.argv = new_array(const char*, 1);
+	unalias.argv = new_array0(const char*, 2);
 	unalias.argv[0] = strdup(opt);
 
 	poptAddAlias(con, unalias, 0);