Merge branch 'jc/renormalize-merge-kill-safer-crlf' into maint

Fix a corner case in merge-recursive regression that crept in
during 2.10 development cycle.

* jc/renormalize-merge-kill-safer-crlf:
  convert: git cherry-pick -Xrenormalize did not work
  merge-recursive: handle NULL in add_cacheinfo() correctly
  cherry-pick: demonstrate a segmentation fault

merge-recursive.c

@@ -235,6 +235,8 @@ static int add_cacheinfo(struct merge_options *o,
 		struct cache_entry *nce;
 
 		nce = refresh_cache_entry(ce, CE_MATCH_REFRESH | CE_MATCH_IGNORE_MISSING);
+		if (!nce)
+			return err(o, _("addinfo_cache failed for path '%s'"), path);
 		if (nce != ce)
 			ret = add_cache_entry(nce, options);
 	}