buildroot/package/busybox/busybox-1.7.4-grep.patch

diff -urN busybox-1.7.4/findutils/grep.c busybox-1.7.4-grep/findutils/grep.c
--- busybox-1.7.4/findutils/grep.c	2007-09-03 04:48:54.000000000 -0700
+++ busybox-1.7.4-grep/findutils/grep.c	2007-12-08 19:02:33.000000000 -0800
@@ -154,14 +154,14 @@
 
 	while ((line = xmalloc_getline(file)) != NULL) {
 		llist_t *pattern_ptr = pattern_head;
-		grep_list_data_t * gl;
+		grep_list_data_t *gl = gl; /* for gcc */
 
 		linenum++;
 		ret = 0;
 		while (pattern_ptr) {
 			gl = (grep_list_data_t *)pattern_ptr->data;
 			if (FGREP_FLAG) {
-				ret = strstr(line, gl->pattern) != NULL;
+				ret |= (strstr(line, gl->pattern) != NULL);
 			} else {
 				/*
 				 * test for a postitive-assertion match (regexec returns success (0)
@@ -255,8 +255,15 @@
 				print_n_lines_after = lines_after;
 #endif
 				if (option_mask32 & OPT_o) {
-					line[regmatch.rm_eo] = '\0';
-					print_line(line + regmatch.rm_so, linenum, ':');
+					if (FGREP_FLAG) {
+						/* -Fo just prints the pattern
+						 * (unless -v: -Fov doesnt print anything at all) */
+						if (ret)
+							print_line(gl->pattern, linenum, ':');
+					} else {
+						line[regmatch.rm_eo] = '\0';
+						print_line(line + regmatch.rm_so, linenum, ':');
+					}
 				} else {
 					print_line(line, linenum, ':');
 				}