*: use llist_pop for traverse-and-free list operation

function                                             old     new   delta
append_file_list_to_list                             109     111      +2
udhcpc_main                                         2414    2413      -1
run_parts_main                                       325     324      -1
od_main                                             2324    2323      -1
getopt_main                                          709     707      -2
env_main                                             253     251      -2
sed_main                                             659     656      -3
ps_main                                              522     519      -3
traceroute_main                                     3960    3954      -6
sort_main                                            844     838      -6
diff_main                                            866     858      -8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/10 up/down: 2/-33)            Total: -31 bytes

14 files changed, 19 insertions, 49 deletions

diff --git a/archival/tar.c b/archival/tar.c
index 64a4e35be..0162e0623 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -659,16 +659,11 @@ int writeTarFile(int tar_fd, int verboseFlag,
 static llist_t *append_file_list_to_list(llist_t *list)
 {
         FILE *src_stream;
-        llist_t *cur = list;
-        llist_t *tmp;
         char *line;
         llist_t *newlist = NULL;
 
-        while (cur) {
-                src_stream = xfopen(cur->data, "r");
-                tmp = cur;
-                cur = cur->link;
-                free(tmp);
+        while (list) {
+                src_stream = xfopen(llist_pop(&list), "r");
                 while ((line = xmalloc_fgetline(src_stream)) != NULL) {
                         /* kill trailing '/' unless the string is just "/" */
                         char *cp = last_char_is(line, '/');
diff --git a/coreutils/env.c b/coreutils/env.c
index e21740d98..8d8753e8b 100644
--- a/coreutils/env.c
+++ b/coreutils/env.c
@@ -62,8 +62,7 @@ int env_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 environ = cleanenv;
         } else {
                 while (unset_env) {
-                        unsetenv(unset_env->data);
-                        unset_env = unset_env->link;
+                        unsetenv(llist_pop(&unset_env));
                 }
         }
 
diff --git a/coreutils/od_bloaty.c b/coreutils/od_bloaty.c
index 5e2287534..ce963db8a 100644
--- a/coreutils/od_bloaty.c
+++ b/coreutils/od_bloaty.c
@@ -1281,8 +1281,7 @@ int od_main(int argc, char **argv)
         if (opt & OPT_o) decode_format_string("o2");
         //if (opt & OPT_t)...
         while (lst_t) {
-                decode_format_string(lst_t->data);
-                lst_t = lst_t->link;
+                decode_format_string(llist_pop(&lst_t));
         }
         if (opt & OPT_v) verbose = 1;
         if (opt & OPT_x) decode_format_string("x2");
diff --git a/coreutils/sort.c b/coreutils/sort.c
index 12b463a6d..1f531fb76 100644
--- a/coreutils/sort.c
+++ b/coreutils/sort.c
@@ -314,7 +314,7 @@ int sort_main(int argc ATTRIBUTE_UNUSED, char **argv)
                         0
                 };
                 struct sort_key *key = add_key();
-                char *str_k = lst_k->data;
+                char *str_k = llist_pop(&lst_k);
                 const char *temp2;
 
                 i = 0; /* i==0 before comma, 1 after (-k3,6) */
@@ -344,8 +344,6 @@ int sort_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                 str_k++;
                         }
                 }
-                /* leaking lst_k... */
-                lst_k = lst_k->link;
         }
 #endif
         /* global b strips leading and trailing spaces */
diff --git a/debianutils/run_parts.c b/debianutils/run_parts.c
index 47eda8cf6..c9b090717 100644
--- a/debianutils/run_parts.c
+++ b/debianutils/run_parts.c
@@ -42,7 +42,7 @@ struct globals {
 #define cur   (G.cur  )
 #define cmd   (G.cmd  )
 
-enum { NUM_CMD = (COMMON_BUFSIZE - sizeof(struct globals)) / sizeof(cmd[0]) };
+enum { NUM_CMD = (COMMON_BUFSIZE - sizeof(G)) / sizeof(cmd[0]) - 1 };
 
 enum {
         OPT_r = (1 << 0),
@@ -130,9 +130,7 @@ int run_parts_main(int argc ATTRIBUTE_UNUSED, char **argv)
 
         n = 1;
         while (arg_list && n < NUM_CMD) {
-                cmd[n] = arg_list->data;
-                arg_list = arg_list->link;
-                n++;
+                cmd[n++] = llist_pop(&arg_list);
         }
         /* cmd[n] = NULL; - is already zeroed out */
 
diff --git a/editors/diff.c b/editors/diff.c
index 4e51f6f76..26f352780 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -1289,14 +1289,9 @@ int diff_main(int argc ATTRIBUTE_UNUSED, char **argv)
         while (L_arg) {
                 if (label1 && label2)
                         bb_show_usage();
-                if (!label1)
-                        label1 = L_arg->data;
-                else { /* then label2 is NULL */
+                if (label1) /* then label2 is NULL */
                         label2 = label1;
-                        label1 = L_arg->data;
-                }
-                /* we leak L_arg here... */
-                L_arg = L_arg->link;
+                label1 = llist_pop(&L_arg);
         }
 
         /*
diff --git a/editors/sed.c b/editors/sed.c
index 817840dc0..bf01fc630 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -1267,21 +1267,17 @@ int sed_main(int argc ATTRIBUTE_UNUSED, char **argv)
         if (opt & 0x2) G.regex_type |= REG_EXTENDED; // -r
         //if (opt & 0x4) G.be_quiet++; // -n
         while (opt_e) { // -e
-                add_cmd_block(opt_e->data);
-                opt_e = opt_e->link;
-                /* we leak opt_e here... */
+                add_cmd_block(llist_pop(&opt_e));
         }
         while (opt_f) { // -f
                 char *line;
                 FILE *cmdfile;
-                cmdfile = xfopen(opt_f->data, "r");
+                cmdfile = xfopen(llist_pop(&opt_f), "r");
                 while ((line = xmalloc_fgetline(cmdfile)) != NULL) {
                         add_cmd(line);
                         free(line);
                 }
                 fclose(cmdfile);
-                opt_f = opt_f->link;
-                /* we leak opt_f here... */
         }
         /* if we didn't get a pattern from -e or -f, use argv[0] */
         if (!(opt & 0x18)) {
diff --git a/findutils/xargs.c b/findutils/xargs.c
index 352f7e64c..3322e9ebd 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -502,7 +502,7 @@ int xargs_main(int argc, char **argv)
                 if (child_error > 0 && child_error != 123) {
                         break;
                 }
-        }
+        } /* while */
         if (ENABLE_FEATURE_CLEAN_UP)
                 free(max_chars);
         return child_error;
diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index 4b5a7d208..86c33483b 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -137,7 +137,7 @@ const char *opt_complementary
         opt_complementary = "vv:b::b-c:c-b";
         f = getopt32(argv, "vb:c", &my_b, &verbose_level);
         if (f & 2)       // -c after -b unsets -b flag
-                while (my_b) { dosomething_with(my_b->data); my_b = my_b->link; }
+                while (my_b) dosomething_with(llist_pop(&my_b));
         if (my_b)        // but llist is stored if -b is specified
                 free_llist(my_b);
         if (verbose_level) printf("verbose level is %d\n", verbose_level);
diff --git a/networking/traceroute.c b/networking/traceroute.c
index e9df27559..6a5373469 100644
--- a/networking/traceroute.c
+++ b/networking/traceroute.c
@@ -1001,17 +1001,11 @@ int traceroute_main(int argc, char **argv)
 
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
         if (source_route_list) {
-                llist_t *l_sr;
-
-                l_sr = source_route_list;
-                while (l_sr) {
+                while (source_route_list) {
                         if (lsrr >= NGATEWAYS)
                                 bb_error_msg_and_die("no more than %d gateways", NGATEWAYS);
-                        getaddr(gwlist + lsrr, l_sr->data);
+                        getaddr(gwlist + lsrr, llist_pop(&source_route_list));
                         ++lsrr;
-                        l_sr = l_sr->link;
-                        free(source_route_list);
-                        source_route_list = l_sr;
                 }
                 optlen = (lsrr + 1) * sizeof(gwlist[0]);
         }
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 655d39fd2..5eb1ed5fd 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -259,12 +259,11 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
         if (opt & OPT_o)
                 client_config.no_default_options = 1;
         while (list_O) {
-                int n = index_in_strings(dhcp_option_strings, list_O->data);
+                int n = index_in_strings(dhcp_option_strings, llist_pop(&list_O));
                 if (n < 0)
                         bb_error_msg_and_die("unknown option '%s'", list_O->data);
                 n = dhcp_options[n].code;
                 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
-                list_O = list_O->link;
         }
 
         if (read_interface(client_config.interface, &client_config.ifindex,
diff --git a/networking/wget.c b/networking/wget.c
index 84ee1ca3e..7198197dd 100644
--- a/networking/wget.c
+++ b/networking/wget.c
@@ -469,8 +469,7 @@ int wget_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 }
                 extra_headers = cp = xmalloc(size);
                 while (headers_llist) {
-                        cp += sprintf(cp, "%s\r\n", headers_llist->data);
-                        headers_llist = headers_llist->link;
+                        cp += sprintf(cp, "%s\r\n", (char*)llist_pop(&headers_llist));
                 }
         }
 #endif
diff --git a/procps/ps.c b/procps/ps.c
index 1ab3973e7..cfca851cf 100644
--- a/procps/ps.c
+++ b/procps/ps.c
@@ -443,8 +443,7 @@ int ps_main(int argc ATTRIBUTE_UNUSED, char **argv)
         USE_SELINUX(opt =) getopt32(argv, "Zo:aAdefl", &opt_o);
         if (opt_o) {
                 do {
-                        parse_o(opt_o->data);
-                        opt_o = opt_o->link;
+                        parse_o(llist_pop(&opt_o));
                 } while (opt_o);
         } else {
                 /* Below: parse_o() needs char*, NOT const char*... */
diff --git a/util-linux/getopt.c b/util-linux/getopt.c
index 31790d2a7..e3b4ca625 100644
--- a/util-linux/getopt.c
+++ b/util-linux/getopt.c
@@ -329,8 +329,7 @@ int getopt_main(int argc, char **argv)
                                         &optstr, &name, &s_arg, &l_arg);
         /* Effectuate the read options for the applet itself */
         while (l_arg) {
-                long_options = add_long_options(long_options, l_arg->data);
-                l_arg = l_arg->link;
+                long_options = add_long_options(long_options, llist_pop(&l_arg));
         }
 #endif