# HG changeset patch
# User Bram Moolenaar <bram@vim.org>
# Date 1362670890 -3600
# Node ID dd669f296568a7525e02ab54b615bde20d37c466
# Parent  905ca4bac04493a7fcdeb01cb86cee5499d8a790
updated for version 7.3.851
Problem:    Using an empty pattern with :sort silently continues when there is
	    no previous search pattern.
Solution:   Give an error message.

diff --git a/src/ex_cmds.c b/src/ex_cmds.c
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -415,8 +415,15 @@ ex_sort(eap)
 	    }
 	    *s = NUL;
 	    /* Use last search pattern if sort pattern is empty. */
-	    if (s == p + 1 && last_search_pat() != NULL)
+	    if (s == p + 1)
+	    {
+		if (last_search_pat() == NULL)
+		{
+		    EMSG(_(e_noprevre));
+		    goto sortend;
+		}
 		regmatch.regprog = vim_regcomp(last_search_pat(), RE_MAGIC);
+	    }
 	    else
 		regmatch.regprog = vim_regcomp(p + 1, RE_MAGIC);
 	    if (regmatch.regprog == NULL)
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -729,6 +729,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    851,
+/**/
     850,
 /**/
     849,