patch 8.2.2811: Vim9: error for missing white space doesn't say where

Problem:    Vim9: error for missing white space doesn't say where it is
            missing
Solution:   Mention the command. (closes #8149)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 46d8115..1c41036 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3673,8 +3673,11 @@
 	    && (eap->cmdidx < 0 ||
 		(cmdnames[eap->cmdidx].cmd_argt & EX_NONWHITE_OK) == 0))
     {
-	semsg(_(e_command_not_followed_by_white_space_str), eap->cmd);
+	char_u *cmd = vim_strnsave(eap->cmd, p - eap->cmd);
+
+	semsg(_(e_command_str_not_followed_by_white_space_str), cmd, eap->cmd);
 	eap->cmdidx = CMD_SIZE;
+	vim_free(cmd);
     }
 #endif