Show warnings for copy, move, multiple remove

src/nnn.c

@@ -3046,11 +3046,24 @@ nochange:
 		case SEL_MV:
 		case SEL_RMMUL:
 		{
+			/* Fail if copy file path not generated */
 			if (!g_cppath[0]) {
 				printmsg("copy file not found");
 				goto nochange;
 			}
 
+			/* Warn if selection not completed */
+			if (cfg.copymode) {
+				printmsg("finish selection first");
+				goto nochange;
+			}
+
+			/* Fail if copy file path isn't created */
+			if (access(g_cppath, R_OK) == -1) {
+				printmsg("empty selection list");
+				goto nochange;
+			}
+
 			if (sel == SEL_CP)
 				snprintf(g_buf, MAX_CMD_LEN, "xargs -0 -d \'\n\' -a %s cp -ir --preserve=all -t .", g_cppath);
 			else if (sel == SEL_MV)