*: kill bb_get_last_path_component, replace with two functions

(one which strips trailing slash and one which does not)
wget: straighten out as a result of above change
   text    data     bss     dec     hex filename
   5056       1       0    5057    13c1 busybox.t4/networking/wget.o
   5022       0       0    5022    139e busybox.t5/networking/wget.o

13 files changed, 66 insertions, 62 deletions

diff --git a/applets/applets.c b/applets/applets.c
index a1a399cd5..5b7b88a54 100644
--- a/applets/applets.c
+++ b/applets/applets.c
@@ -601,7 +601,7 @@ static int busybox_main(char **argv)
         }
         /* We support "busybox /a/path/to/applet args..." too. Allows for
          * "#!/bin/busybox"-style wrappers */
-        applet_name = bb_get_last_path_component(argv[0]);
+        applet_name = bb_get_last_path_component_nostrip(argv[0]);
         run_applet_and_exit(applet_name, argv);
         bb_error_msg_and_die("applet not found");
 }
diff --git a/coreutils/basename.c b/coreutils/basename.c
index f59d7a8de..ec1f85bef 100644
--- a/coreutils/basename.c
+++ b/coreutils/basename.c
@@ -34,7 +34,8 @@ int basename_main(int argc, char **argv)
                 bb_show_usage();
         }
 
-        s = bb_get_last_path_component(*++argv);
+        /* It should strip slash: /abc/def/ -> def */
+        s = bb_get_last_path_component_strip(*++argv);
 
         if (*++argv) {
                 n = strlen(*argv);
diff --git a/coreutils/cp.c b/coreutils/cp.c
index 76dc566b3..889e4604d 100644
--- a/coreutils/cp.c
+++ b/coreutils/cp.c
@@ -87,7 +87,7 @@ int cp_main(int argc, char **argv)
         }
 
         while (1) {
-                dest = concat_path_file(last, bb_get_last_path_component(*argv));
+                dest = concat_path_file(last, bb_get_last_path_component_strip(*argv));
  DO_COPY:
                 if (copy_file(*argv, dest, flags) < 0) {
                         status = 1;
diff --git a/coreutils/ln.c b/coreutils/ln.c
index a6499039e..f3c67aa36 100644
--- a/coreutils/ln.c
+++ b/coreutils/ln.c
@@ -45,7 +45,7 @@ int ln_main(int argc, char **argv)
 
         if (argc == optind + 1) {
                 *--argv = last;
-                last = bb_get_last_path_component(xstrdup(last));
+                last = bb_get_last_path_component_strip(xstrdup(last));
         }
 
         do {
@@ -57,7 +57,7 @@ int ln_main(int argc, char **argv)
                                 NULL)
                 ) {
                         src_name = xstrdup(*argv);
-                        src = concat_path_file(src, bb_get_last_path_component(src_name));
+                        src = concat_path_file(src, bb_get_last_path_component_strip(src_name));
                         free(src_name);
                         src_name = src;
                 }
diff --git a/coreutils/mv.c b/coreutils/mv.c
index 1d2977060..d13f4d54f 100644
--- a/coreutils/mv.c
+++ b/coreutils/mv.c
@@ -68,7 +68,7 @@ int mv_main(int argc, char **argv)
         }
 
         do {
-                dest = concat_path_file(last, bb_get_last_path_component(*argv));
+                dest = concat_path_file(last, bb_get_last_path_component_strip(*argv));
                 dest_exists = cp_mv_stat(dest, &dest_stat);
                 if (dest_exists < 0) {
                         goto RET_1;
diff --git a/coreutils/rm.c b/coreutils/rm.c
index ba37762a8..a686fc40c 100644
--- a/coreutils/rm.c
+++ b/coreutils/rm.c
@@ -38,7 +38,7 @@ int rm_main(int argc, char **argv)
 
         if (*argv != NULL) {
                 do {
-                        const char *base = bb_get_last_path_component(*argv);
+                        const char *base = bb_get_last_path_component_strip(*argv);
 
                         if (DOT_OR_DOTDOT(base)) {
                                 bb_error_msg("cannot remove '.' or '..'");
diff --git a/include/libbb.h b/include/libbb.h
index e5f03517f..25b2e4489 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -236,9 +236,15 @@ extern void bb_copyfd_exact_size(int fd1, int fd2, off_t size);
 /* this helper yells "short read!" if param is not -1 */
 extern void complain_copyfd_and_die(off_t sz) ATTRIBUTE_NORETURN;
 extern char bb_process_escape_sequence(const char **ptr);
-/* TODO: sometimes modifies its parameter, which
- * makes it rather inconvenient at times: */
-extern char *bb_get_last_path_component(char *path);
+/* xxxx_strip version can modify its parameter:
+ * "/"        -> "/"
+ * "abc"      -> "abc"
+ * "abc/def"  -> "def"
+ * "abc/def/" -> "def" !!
+ */
+extern char *bb_get_last_path_component_strip(char *path);
+/* "abc/def/" -> "" and it never modifies 'path' */
+extern char *bb_get_last_path_component_nostrip(const char *path);
 
 int ndelay_on(int fd);
 int ndelay_off(int fd);
diff --git a/init/init.c b/init/init.c
index a196ab3ed..543ec2ea8 100644
--- a/init/init.c
+++ b/init/init.c
@@ -436,10 +436,11 @@ static pid_t run(const struct init_action *a)
                 ++cmdpath;
 
                 /* find the last component in the command pathname */
-                s = bb_get_last_path_component(cmdpath);
+                s = bb_get_last_path_component_nostrip(cmdpath);
 
                 /* make a new argv[0] */
-                if ((cmd[0] = malloc(strlen(s) + 2)) == NULL) {
+                cmd[0] = malloc(strlen(s) + 2);
+                if (cmd[0] == NULL) {
                         message(L_LOG | L_CONSOLE, bb_msg_memory_exhausted);
                         cmd[0] = cmdpath;
                 } else {
diff --git a/libbb/get_last_path_component.c b/libbb/get_last_path_component.c
index b7bc0e626..0f602157d 100644
--- a/libbb/get_last_path_component.c
+++ b/libbb/get_last_path_component.c
@@ -8,25 +8,35 @@
  */
 
 #include "libbb.h"
-
-char *bb_get_last_path_component(char *path)
+/*
+ * "/"        -> "/"
+ * "abc"      -> "abc"
+ * "abc/def"  -> "def"
+ * "abc/def/" -> ""
+ */
+char *bb_get_last_path_component_nostrip(const char *path)
 {
-        char *first = path;
-        char *last;
+        char *slash = strrchr(path, '/');
+
+        if (!slash || (slash == path && !slash[1]))
+                return (char*)path;
 
-        last = path - 1;
+        return slash + 1;
+}
 
-        while (*path) {
-                if ((*path != '/') && (path > ++last)) {
-                        last = first = path;
-                }
-                ++path;
-        }
+/*
+ * "/"        -> "/"
+ * "abc"      -> "abc"
+ * "abc/def"  -> "def"
+ * "abc/def/" -> "def" !!
+ */
+char *bb_get_last_path_component_strip(char *path)
+{
+        char *slash = last_char_is(path, '/');
 
-        if (*first == '/') {
-                last = first;
-        }
-        last[1] = '\0';
+        if (slash)
+                while (*slash == '/' && slash != path)
+                        *slash-- = '\0';
 
-        return first;
+        return bb_get_last_path_component_nostrip(path);
 }
diff --git a/libbb/run_shell.c b/libbb/run_shell.c
index b2b4216f4..239887d85 100644
--- a/libbb/run_shell.c
+++ b/libbb/run_shell.c
@@ -67,7 +67,7 @@ void run_shell(const char *shell, int loginshell, const char *command, const cha
 
         args = xmalloc(sizeof(char*) * (4 + additional_args_cnt));
 
-        args[0] = bb_get_last_path_component(xstrdup(shell));
+        args[0] = bb_get_last_path_component_nostrip(xstrdup(shell));
 
         if (loginshell)
                 args[0] = xasprintf("-%s", args[0]);
diff --git a/modutils/insmod.c b/modutils/insmod.c
index 503367298..0baf5d7f2 100644
--- a/modutils/insmod.c
+++ b/modutils/insmod.c
@@ -806,7 +806,7 @@ static int check_module_name_match(const char *filename, struct stat *statbuf,
                 return FALSE;
         else {
                 char *tmp, *tmp1 = xstrdup(filename);
-                tmp = bb_get_last_path_component(tmp1);
+                tmp = bb_get_last_path_component_nostrip(tmp1);
                 if (strcmp(tmp, fullname) == 0) {
                         free(tmp1);
                         /* Stop searching if we find a match */
diff --git a/networking/wget.c b/networking/wget.c
index 5feb539d5..86d6f00ec 100644
--- a/networking/wget.c
+++ b/networking/wget.c
@@ -12,11 +12,11 @@
 struct host_info {
         // May be used if we ever will want to free() all xstrdup()s...
         /* char *allocated; */
-        char    *path;
-        char    *user;
-        char    *host;
-        int      port;
-        smallint is_ftp;
+        const char *path;
+        const char *user;
+        char       *host;
+        int         port;
+        smallint    is_ftp;
 };
 
 
@@ -318,9 +318,7 @@ static void parse_url(char *src_url, struct host_info *h)
         p = strchr(h->host, '?'); if (!sp || (p && sp > p)) sp = p;
         p = strchr(h->host, '#'); if (!sp || (p && sp > p)) sp = p;
         if (!sp) {
-                /* must be writable because of bb_get_last_path_component() */
-                static char nullstr[] ALIGN1 = "";
-                h->path = nullstr;
+                h->path = "";
         } else if (*sp == '/') {
                 *sp = '\0';
                 h->path = sp + 1;
@@ -328,7 +326,7 @@ static void parse_url(char *src_url, struct host_info *h)
                 // http://busybox.net?login=john@doe is a valid URL
                 // memmove converts to:
                 // http:/busybox.nett?login=john@doe...
-                memmove(h->host-1, h->host, sp - h->host);
+                memmove(h->host - 1, h->host, sp - h->host);
                 h->host--;
                 sp[-1] = '\0';
                 h->path = sp;
@@ -497,31 +495,20 @@ int wget_main(int argc, char **argv)
                 }
         }
 
-        /* Guess an output filename */
+        /* Guess an output filename, if there was no -O FILE */
         if (!fname_out) {
-                // Dirty hack. Needed because bb_get_last_path_component
-                // will destroy trailing / by storing '\0' in last byte!
-                if (!last_char_is(target.path, '/')) {
-                        fname_out = bb_get_last_path_component(target.path);
-#if ENABLE_FEATURE_WGET_STATUSBAR
-                        curfile = fname_out;
-#endif
-                }
-                if (!fname_out || !fname_out[0]) {
-                        /* bb_get_last_path_component writes
-                         * to last '/' only. We don't have one here... */
+                fname_out = bb_get_last_path_component_nostrip(target.path);
+                /* handle "wget http://kernel.org//" */
+                if (fname_out[0] == '/' || !fname_out[0])
                         fname_out = (char*)"index.html";
-#if ENABLE_FEATURE_WGET_STATUSBAR
-                        curfile = fname_out;
-#endif
-                }
-                if (dir_prefix != NULL)
+                /* -P DIR is considered only if there was no -O FILE */
+                if (dir_prefix)
                         fname_out = concat_path_file(dir_prefix, fname_out);
+        }
 #if ENABLE_FEATURE_WGET_STATUSBAR
-        } else {
-                curfile = bb_get_last_path_component(fname_out);
+        curfile = bb_get_last_path_component_nostrip(fname_out);
 #endif
-        }
+
         /* Impossible?
         if ((opt & WGET_OPT_CONTINUE) && !fname_out)
                 bb_error_msg_and_die("cannot specify continue (-c) without a filename (-O)"); */
diff --git a/shell/lash.c b/shell/lash.c
index d4dba8e63..889fe49d8 100644
--- a/shell/lash.c
+++ b/shell/lash.c
@@ -1141,12 +1141,11 @@ static int pseudo_exec(struct child_prog *child)
                 }
         }
 
-
         /* Check if the command matches any busybox internal
          * commands ("applets") here.  Following discussions from
          * November 2000 on busybox@busybox.net, don't use
-         * bb_get_last_path_component().  This way explicit (with
-         * slashes) filenames will never be interpreted as an
+         * bb_get_last_path_component_nostrip().  This way explicit
+         * (with slashes) filenames will never be interpreted as an
          * applet, just like with builtins.  This way the user can
          * override an applet with an explicit filename reference.
          * The only downside to this change is that an explicit