Cosmetic changes to file_compare() for readability and to
[rsync/rsync.git] / flist.c
diff --git a/flist.c b/flist.c
index 7166762..a14ce5f 100644 (file)
--- a/flist.c
+++ b/flist.c
@@ -58,7 +58,6 @@ extern int implied_dirs;
 extern int copy_links;
 extern int copy_unsafe_links;
 extern int protocol_version;
-extern int io_error;
 extern int sanitize_paths;
 
 extern int read_batch;
@@ -68,6 +67,8 @@ extern struct exclude_struct **exclude_list;
 extern struct exclude_struct **server_exclude_list;
 extern struct exclude_struct **local_exclude_list;
 
+int io_error;
+
 static struct file_struct null_file;
 
 static void clean_flist(struct file_list *flist, int strip_root, int no_dups);
@@ -106,9 +107,8 @@ static void finish_filelist_progress(const struct file_list *flist)
                /* This overwrites the progress line */
                rprintf(FINFO, "%d file%sto consider\n",
                        flist->count, flist->count == 1 ? " " : "s ");
-       } else {
+       } else
                rprintf(FINFO, "done\n");
-       }
 }
 
 void show_flist_stats(void)
@@ -123,10 +123,10 @@ static struct string_area *string_area_new(int size)
 
        if (size <= 0)
                size = ARENA_SIZE;
-       a = malloc(sizeof(*a));
+       a = new(struct string_area);
        if (!a)
                out_of_memory("string_area_new");
-       a->current = a->base = malloc(size);
+       a->current = a->base = new_array(char, size);
        if (!a->current)
                out_of_memory("string_area_new buffer");
        a->end = a->base + size;
@@ -209,18 +209,15 @@ static void list_file_entry(struct file_struct *f)
  * @post @p buffer contains information about the link or the
  * referrent as appropriate, if they exist.
  **/
-int readlink_stat(const char *path, STRUCT_STAT * buffer, char *linkbuf)
+int readlink_stat(const char *path, STRUCT_STAT *buffer, char *linkbuf)
 {
 #if SUPPORT_LINKS
-       if (copy_links) {
+       if (copy_links)
                return do_stat(path, buffer);
-       }
-       if (do_lstat(path, buffer) == -1) {
+       if (do_lstat(path, buffer) == -1)
                return -1;
-       }
        if (S_ISLNK(buffer->st_mode)) {
-               int l;
-               l = readlink((char *) path, linkbuf, MAXPATHLEN - 1);
+               int l = readlink((char *) path, linkbuf, MAXPATHLEN - 1);
                if (l == -1)
                        return -1;
                linkbuf[l] = 0;
@@ -241,11 +238,9 @@ int readlink_stat(const char *path, STRUCT_STAT * buffer, char *linkbuf)
 int link_stat(const char *path, STRUCT_STAT * buffer)
 {
 #if SUPPORT_LINKS
-       if (copy_links) {
+       if (copy_links)
                return do_stat(path, buffer);
-       } else {
-               return do_lstat(path, buffer);
-       }
+       return do_lstat(path, buffer);
 #else
        return do_stat(path, buffer);
 #endif
@@ -300,17 +295,15 @@ static void set_filesystem(char *fname)
 
 static int to_wire_mode(mode_t mode)
 {
-       if (S_ISLNK(mode) && (_S_IFLNK != 0120000)) {
+       if (S_ISLNK(mode) && (_S_IFLNK != 0120000))
                return (mode & ~(_S_IFMT)) | 0120000;
-       }
        return (int) mode;
 }
 
 static mode_t from_wire_mode(int mode)
 {
-       if ((mode & (_S_IFMT)) == 0120000 && (_S_IFLNK != 0120000)) {
+       if ((mode & (_S_IFMT)) == 0120000 && (_S_IFLNK != 0120000))
                return (mode & ~(_S_IFMT)) | _S_IFLNK;
-       }
        return (mode_t) mode;
 }
 
@@ -327,7 +320,6 @@ static char *flist_dir;
 static void flist_expand(struct file_list *flist)
 {
        if (flist->count >= flist->malloced) {
-               size_t new_bytes;
                void *new_ptr;
 
                if (flist->malloced < 1000)
@@ -335,16 +327,19 @@ static void flist_expand(struct file_list *flist)
                else
                        flist->malloced *= 2;
 
-               new_bytes = sizeof(flist->files[0]) * flist->malloced;
-
-               if (flist->files)
-                       new_ptr = realloc(flist->files, new_bytes);
-               else
-                       new_ptr = malloc(new_bytes);
+               if (flist->files) {
+                       new_ptr = realloc_array(flist->files,
+                                               struct file_struct *,
+                                               flist->malloced);
+               } else {
+                       new_ptr = new_array(struct file_struct *,
+                                           flist->malloced);
+               }
 
                if (verbose >= 2) {
                        rprintf(FINFO, "expand file_list to %.0f bytes, did%s move\n",
-                               (double) new_bytes,
+                               (double)sizeof(flist->files[0])
+                               * flist->malloced,
                                (new_ptr == flist->files) ? " not" : "");
                }
 
@@ -366,7 +361,7 @@ static void send_file_entry(struct file_struct *file, int f,
        static uid_t last_uid;
        static gid_t last_gid;
        static char lastname[MAXPATHLEN];
-       char *fname;
+       char *fname, fbuf[MAXPATHLEN];
        int l1, l2;
 
        if (f == -1)
@@ -379,7 +374,7 @@ static void send_file_entry(struct file_struct *file, int f,
 
        io_write_phase = "send_file_entry";
 
-       fname = f_name(file);
+       fname = f_name_to(file, fbuf, sizeof fbuf);
 
        flags = base_flags;
 
@@ -459,11 +454,10 @@ static void send_file_entry(struct file_struct *file, int f,
 #endif
 
        if (always_checksum) {
-               if (protocol_version < 21) {
+               if (protocol_version < 21)
                        write_buf(f, file->sum, 2);
-               } else {
+               else
                        write_buf(f, file->sum, MD4_SUM_LENGTH);
-               }
        }
 
        last_mode = file->mode;
@@ -502,7 +496,7 @@ static void receive_file_entry(struct file_struct **fptr,
        else
                l2 = read_byte(f);
 
-       file = (struct file_struct *) malloc(sizeof(*file));
+       file = new(struct file_struct);
        if (!file)
                out_of_memory("receive_file_entry");
        memset((char *) file, 0, sizeof(*file));
@@ -531,9 +525,9 @@ static void receive_file_entry(struct file_struct **fptr,
        if ((p = strrchr(thisname, '/'))) {
                static char *lastdir;
                *p = 0;
-               if (lastdir && strcmp(thisname, lastdir) == 0) {
+               if (lastdir && strcmp(thisname, lastdir) == 0)
                        file->dirname = lastdir;
-               else {
+               else {
                        file->dirname = strdup(thisname);
                        lastdir = file->dirname;
                }
@@ -546,22 +540,19 @@ static void receive_file_entry(struct file_struct **fptr,
        if (!file->basename)
                out_of_memory("receive_file_entry 1");
 
-
        file->flags = flags;
        file->length = read_longint(f);
-       file->modtime =
-           (flags & SAME_TIME) ? last_time : (time_t) read_int(f);
-       file->mode =
-           (flags & SAME_MODE) ? last_mode : from_wire_mode(read_int(f));
+       file->modtime = (flags & SAME_TIME) ? last_time : (time_t)read_int(f);
+       file->mode = (flags & SAME_MODE) ? last_mode
+                                        : from_wire_mode(read_int(f));
        if (preserve_uid)
-               file->uid =
-                   (flags & SAME_UID) ? last_uid : (uid_t) read_int(f);
+               file->uid = (flags & SAME_UID) ? last_uid : (uid_t)read_int(f);
        if (preserve_gid)
-               file->gid =
-                   (flags & SAME_GID) ? last_gid : (gid_t) read_int(f);
-       if (preserve_devices && IS_DEVICE(file->mode))
-               file->rdev =
-                   (flags & SAME_RDEV) ? last_rdev : (DEV64_T) read_int(f);
+               file->gid = (flags & SAME_GID) ? last_gid : (gid_t)read_int(f);
+       if (preserve_devices && IS_DEVICE(file->mode)) {
+               file->rdev = (flags & SAME_RDEV) ? last_rdev
+                                                : (DEV64_T)read_int(f);
+       }
 
        if (preserve_links && S_ISLNK(file->mode)) {
                int l = read_int(f);
@@ -569,13 +560,12 @@ static void receive_file_entry(struct file_struct **fptr,
                        rprintf(FERROR, "overflow: l=%d\n", l);
                        overflow("receive_file_entry");
                }
-               file->link = (char *) malloc(l + 1);
+               file->link = new_array(char, l + 1);
                if (!file->link)
                        out_of_memory("receive_file_entry 2");
                read_sbuf(f, file->link, l);
-               if (sanitize_paths) {
+               if (sanitize_paths)
                        sanitize_path(file->link, file->dirname);
-               }
        }
 #if SUPPORT_HARD_LINKS
        if (preserve_hard_links && S_ISREG(file->mode)) {
@@ -590,14 +580,13 @@ static void receive_file_entry(struct file_struct **fptr,
 #endif
 
        if (always_checksum) {
-               file->sum = (char *) malloc(MD4_SUM_LENGTH);
+               file->sum = new_array(char, MD4_SUM_LENGTH);
                if (!file->sum)
                        out_of_memory("md4 sum");
-               if (protocol_version < 21) {
+               if (protocol_version < 21)
                        read_buf(f, file->sum, 2);
-               } else {
+               else
                        read_buf(f, file->sum, MD4_SUM_LENGTH);
-               }
        }
 
        last_mode = file->mode;
@@ -674,9 +663,8 @@ struct file_struct *make_file(char *fname, struct string_area **ap,
        strlcpy(cleaned_name, fname, MAXPATHLEN);
        cleaned_name[MAXPATHLEN - 1] = 0;
        clean_fname(cleaned_name);
-       if (sanitize_paths) {
+       if (sanitize_paths)
                sanitize_path(cleaned_name, NULL);
-       }
        fname = cleaned_name;
 
        memset(sum, 0, SUM_LENGTH);
@@ -692,9 +680,9 @@ struct file_struct *make_file(char *fname, struct string_area **ap,
                                return NULL;
                        }
                }
-               io_error = 1;
-               rprintf(FERROR, "readlink %s: %s\n",
-                       fname, strerror(save_errno));
+               io_error |= IOERR_GENERAL;
+               rprintf(FERROR, "readlink %s failed: %s\n",
+                       full_fname(fname), strerror(save_errno));
                return NULL;
        }
 
@@ -723,7 +711,7 @@ struct file_struct *make_file(char *fname, struct string_area **ap,
        if (verbose > 2)
                rprintf(FINFO, "make_file(%s,*,%d)\n", fname, exclude_level);
 
-       file = (struct file_struct *) malloc(sizeof(*file));
+       file = new(struct file_struct);
        if (!file)
                out_of_memory("make_file");
        memset((char *) file, 0, sizeof(*file));
@@ -731,9 +719,9 @@ struct file_struct *make_file(char *fname, struct string_area **ap,
        if ((p = strrchr(fname, '/'))) {
                static char *lastdir;
                *p = 0;
-               if (lastdir && strcmp(fname, lastdir) == 0) {
+               if (lastdir && strcmp(fname, lastdir) == 0)
                        file->dirname = lastdir;
-               else {
+               else {
                        file->dirname = strdup(fname);
                        lastdir = file->dirname;
                }
@@ -756,9 +744,8 @@ struct file_struct *make_file(char *fname, struct string_area **ap,
 #endif
 
 #if SUPPORT_LINKS
-       if (S_ISLNK(st.st_mode)) {
+       if (S_ISLNK(st.st_mode))
                file->link = STRDUP(ap, linkbuf);
-       }
 #endif
 
        if (always_checksum) {
@@ -777,15 +764,14 @@ struct file_struct *make_file(char *fname, struct string_area **ap,
 
        if (flist_dir) {
                static char *lastdir;
-               if (lastdir && strcmp(lastdir, flist_dir) == 0) {
+               if (lastdir && strcmp(lastdir, flist_dir) == 0)
                        file->basedir = lastdir;
-               else {
+               else {
                        file->basedir = strdup(flist_dir);
                        lastdir = file->basedir;
                }
-       } else {
+       } else
                file->basedir = NULL;
-       }
 
        if (!S_ISDIR(st.st_mode))
                stats.total_size += st.st_size;
@@ -794,11 +780,11 @@ struct file_struct *make_file(char *fname, struct string_area **ap,
 }
 
 
-
 void send_file_name(int f, struct file_list *flist, char *fname,
                    int recursive, unsigned base_flags)
 {
        struct file_struct *file;
+       char fbuf[MAXPATHLEN];
        extern int delete_excluded;
 
        /* f is set to -1 when calculating deletion file list */
@@ -813,7 +799,7 @@ void send_file_name(int f, struct file_list *flist, char *fname,
 
        flist_expand(flist);
 
-       if (write_batch)        /*  dw  */
+       if (write_batch)
                file->flags = FLAG_DELETE;
 
        if (file->basename[0]) {
@@ -824,14 +810,13 @@ void send_file_name(int f, struct file_list *flist, char *fname,
        if (S_ISDIR(file->mode) && recursive) {
                struct exclude_struct **last_exclude_list =
                    local_exclude_list;
-               send_directory(f, flist, f_name(file));
+               send_directory(f, flist, f_name_to(file, fbuf, sizeof fbuf));
                local_exclude_list = last_exclude_list;
                return;
        }
 }
 
 
-
 static void send_directory(int f, struct file_list *flist, char *dir)
 {
        DIR *d;
@@ -842,8 +827,9 @@ static void send_directory(int f, struct file_list *flist, char *dir)
 
        d = opendir(dir);
        if (!d) {
-               io_error = 1;
-               rprintf(FERROR, "opendir(%s): %s\n", dir, strerror(errno));
+               io_error |= IOERR_GENERAL;
+               rprintf(FERROR, "opendir %s failed: %s\n",
+                       full_fname(dir), strerror(errno));
                return;
        }
 
@@ -851,10 +837,9 @@ static void send_directory(int f, struct file_list *flist, char *dir)
        l = strlen(fname);
        if (fname[l - 1] != '/') {
                if (l == MAXPATHLEN - 1) {
-                       io_error = 1;
-                       rprintf(FERROR,
-                               "skipping long-named directory %s\n",
-                               fname);
+                       io_error |= IOERR_GENERAL;
+                       rprintf(FERROR, "skipping long-named directory: %s\n",
+                               full_fname(fname));
                        closedir(d);
                        return;
                }
@@ -870,21 +855,26 @@ static void send_directory(int f, struct file_list *flist, char *dir)
                        strcpy(p, ".cvsignore");
                        add_exclude_file(&exclude_list,fname,MISSING_OK,ADD_EXCLUDE);
                } else {
-                       io_error = 1;
+                       io_error |= IOERR_GENERAL;
                        rprintf(FINFO,
                                "cannot cvs-exclude in long-named directory %s\n",
-                               fname);
+                               full_fname(fname));
                }
        }
 
-       for (di = readdir(d); di; di = readdir(d)) {
+       for (errno = 0, di = readdir(d); di; errno = 0, di = readdir(d)) {
                char *dname = d_name(di);
-               if (dname[0] == '.' && (dname[1] == '\0' ||
-                   (dname[1] == '.' && dname[2] == '\0')))
+               if (dname[0] == '.' && (dname[1] == '\0'
+                   || (dname[1] == '.' && dname[2] == '\0')))
                        continue;
                strlcpy(p, dname, MAXPATHLEN - l);
                send_file_name(f, flist, fname, recurse, 0);
        }
+       if (errno) {
+               io_error |= IOERR_GENERAL;
+               rprintf(FERROR, "readdir(%s): (%d) %s\n",
+                   dir, errno, strerror(errno));
+       }
 
        if (local_exclude_list)
                free_exclude_list(&local_exclude_list); /* Zeros pointer too */
@@ -917,11 +907,11 @@ struct file_list *send_file_list(int f, int argc, char *argv[])
        flist = flist_new();
 
        if (f != -1) {
-               io_start_buffering(f);
+               io_start_buffering_out(f);
                if (filesfrom_fd >= 0) {
                        if (argv[0] && !push_dir(argv[0], 0)) {
-                               rprintf(FERROR, "push_dir %s : %s\n",
-                                       argv[0], strerror(errno));
+                               rprintf(FERROR, "push_dir %s failed: %s\n",
+                                       full_fname(argv[0]), strerror(errno));
                                exit_cleanup(RERR_FILESELECT);
                        }
                        use_ff_fd = 1;
@@ -956,9 +946,9 @@ struct file_list *send_file_list(int f, int argc, char *argv[])
 
                if (link_stat(fname, &st) != 0) {
                        if (f != -1) {
-                               io_error = 1;
-                               rprintf(FERROR, "link_stat %s : %s\n",
-                                       fname, strerror(errno));
+                               io_error |= IOERR_GENERAL;
+                               rprintf(FERROR, "link_stat %s failed: %s\n",
+                                       full_fname(fname), strerror(errno));
                        }
                        continue;
                }
@@ -1023,9 +1013,9 @@ struct file_list *send_file_list(int f, int argc, char *argv[])
                        olddir = push_dir(dir, 1);
 
                        if (!olddir) {
-                               io_error = 1;
-                               rprintf(FERROR, "push_dir %s : %s\n",
-                                       dir, strerror(errno));
+                               io_error |= IOERR_GENERAL;
+                               rprintf(FERROR, "push_dir %s failed: %s\n",
+                                       full_fname(dir), strerror(errno));
                                continue;
                        }
 
@@ -1040,28 +1030,25 @@ struct file_list *send_file_list(int f, int argc, char *argv[])
                if (olddir != NULL) {
                        flist_dir = NULL;
                        if (pop_dir(olddir) != 0) {
-                               rprintf(FERROR, "pop_dir %s : %s\n",
-                                       dir, strerror(errno));
+                               rprintf(FERROR, "pop_dir %s failed: %s\n",
+                                       full_fname(dir), strerror(errno));
                                exit_cleanup(RERR_FILESELECT);
                        }
                }
        }
 
-       if (f != -1) {
+       if (f != -1)
                send_file_entry(NULL, f, 0);
-       }
 
-       if (show_filelist_p() && f != -1) {
+       if (show_filelist_p() && f != -1)
                finish_filelist_progress(flist);
-       }
 
        clean_flist(flist, 0, 0);
 
        /* now send the uid/gid list. This was introduced in protocol
           version 15 */
-       if (f != -1) {
+       if (f != -1)
                send_uid_list(f);
-       }
 
        /* send the io_error flag */
        if (f != -1) {
@@ -1073,7 +1060,7 @@ struct file_list *send_file_list(int f, int argc, char *argv[])
                io_end_buffering();
                stats.flist_size = stats.total_written - start_write;
                stats.num_files = flist->count;
-               if (write_batch)        /*  dw  */
+               if (write_batch)
                        write_batch_flist_info(flist->count, flist->files);
        }
 
@@ -1096,15 +1083,13 @@ struct file_list *recv_file_list(int f)
 
        start_read = stats.total_read;
 
-       flist = (struct file_list *) malloc(sizeof(flist[0]));
+       flist = new(struct file_list);
        if (!flist)
                goto oom;
 
        flist->count = 0;
        flist->malloced = 1000;
-       flist->files =
-           (struct file_struct **) malloc(sizeof(flist->files[0]) *
-                                          flist->malloced);
+       flist->files = new_array(struct file_struct *, flist->malloced);
        if (!flist->files)
                goto oom;
 
@@ -1123,9 +1108,10 @@ struct file_list *recv_file_list(int f)
 
                maybe_emit_filelist_progress(flist);
 
-               if (verbose > 2)
+               if (verbose > 2) {
                        rprintf(FINFO, "recv_file_name(%s)\n",
                                f_name(flist->files[i]));
+               }
        }
 
 
@@ -1134,31 +1120,27 @@ struct file_list *recv_file_list(int f)
 
        clean_flist(flist, relative_paths, 1);
 
-       if (show_filelist_p()) {
+       if (show_filelist_p())
                finish_filelist_progress(flist);
-       }
 
        /* now recv the uid/gid list. This was introduced in protocol version 15 */
-       if (f != -1) {
+       if (f != -1)
                recv_uid_list(f, flist);
-       }
 
        /* recv the io_error flag */
        if (f != -1 && !read_batch) {   /* dw-added readbatch */
                extern int module_id;
                extern int ignore_errors;
-               if (lp_ignore_errors(module_id) || ignore_errors) {
+               if (lp_ignore_errors(module_id) || ignore_errors)
                        read_int(f);
-               } else {
+               else
                        io_error |= read_int(f);
-               }
        }
 
        if (list_only) {
                int i;
-               for (i = 0; i < flist->count; i++) {
+               for (i = 0; i < flist->count; i++)
                        list_file_entry(flist->files[i]);
-               }
        }
 
 
@@ -1176,21 +1158,20 @@ struct file_list *recv_file_list(int f)
 }
 
 
-/*
- * XXX: This is currently the hottest function while building the file
- * list, because building f_name()s every time is expensive.
- **/
-int file_compare(struct file_struct **f1, struct file_struct **f2)
+int file_compare(struct file_struct **file1, struct file_struct **file2)
 {
-       if (!(*f1)->basename && !(*f2)->basename)
+       struct file_struct *f1 = *file1;
+       struct file_struct *f2 = *file2;
+
+       if (!f1->basename && !f2->basename)
                return 0;
-       if (!(*f1)->basename)
+       if (!f1->basename)
                return -1;
-       if (!(*f2)->basename)
+       if (!f2->basename)
                return 1;
-       if ((*f1)->dirname == (*f2)->dirname)
-               return u_strcmp((*f1)->basename, (*f2)->basename);
-       return u_strcmp(f_name(*f1), f_name(*f2));
+       if (f1->dirname == f2->dirname)
+               return u_strcmp(f1->basename, f2->basename);
+       return f_name_cmp(f1, f2);
 }
 
 
@@ -1205,15 +1186,13 @@ int flist_find(struct file_list *flist, struct file_struct *f)
 
        while (low != high) {
                int mid = (low + high) / 2;
-               int ret =
-                   file_compare(&flist->files[flist_up(flist, mid)], &f);
+               int ret = file_compare(&flist->files[flist_up(flist, mid)],&f);
                if (ret == 0)
                        return flist_up(flist, mid);
-               if (ret > 0) {
+               if (ret > 0)
                        high = mid;
-               } else {
+               else
                        low = mid + 1;
-               }
        }
 
        if (file_compare(&flist->files[flist_up(flist, low)], &f) == 0)
@@ -1246,7 +1225,7 @@ struct file_list *flist_new(void)
 {
        struct file_list *flist;
 
-       flist = (struct file_list *) malloc(sizeof(flist[0]));
+       flist = new(struct file_list);
        if (!flist)
                out_of_memory("send_file_list");
 
@@ -1294,7 +1273,6 @@ void flist_free(struct file_list *flist)
 static void clean_flist(struct file_list *flist, int strip_root, int no_dups)
 {
        int i, prev_i = 0;
-       char *name, *prev_name = NULL;
 
        if (!flist || flist->count == 0)
                return;
@@ -1305,19 +1283,17 @@ static void clean_flist(struct file_list *flist, int strip_root, int no_dups)
        for (i = no_dups? 0 : flist->count; i < flist->count; i++) {
                if (flist->files[i]->basename) {
                        prev_i = i;
-                       prev_name = f_name(flist->files[i]);
                        break;
                }
        }
        while (++i < flist->count) {
                if (!flist->files[i]->basename)
                        continue;
-               name = f_name(flist->files[i]);
-               if (strcmp(name, prev_name) == 0) {
+               if (f_name_cmp(flist->files[i], flist->files[prev_i]) == 0) {
                        if (verbose > 1 && !am_server) {
                                rprintf(FINFO,
                                        "removing duplicate name %s from file list %d\n",
-                                       name, i);
+                                       f_name(flist->files[i]), i);
                        }
                        /* Make sure that if we unduplicate '.', that we don't
                         * lose track of a user-specified starting point (or
@@ -1335,9 +1311,6 @@ static void clean_flist(struct file_list *flist, int strip_root, int no_dups)
                }
                else
                        prev_i = i;
-               /* We set prev_name every iteration to avoid it becoming
-                * invalid when names[][] in f_name() wraps around. */
-               prev_name = name;
        }
 
        if (strip_root) {
@@ -1373,33 +1346,100 @@ static void clean_flist(struct file_list *flist, int strip_root, int no_dups)
 }
 
 
-/*
- * return the full filename of a flist entry
- *
- * This function is too expensive at the moment, because it copies
- * strings when often we only want to compare them.  In any case,
- * using strlcat is silly because it will walk the string repeatedly.
+enum fnc_state { fnc_DIR, fnc_SLASH, fnc_BASE };
+
+/* Compare the names of two file_struct entities, just like strcmp()
+ * would do if it were operating on the joined strings.  We assume
+ * that there are no 0-length strings.
  */
-char *f_name(struct file_struct *f)
+int f_name_cmp(struct file_struct *f1, struct file_struct *f2)
 {
-       static char names[10][MAXPATHLEN];
-       static int n;
-       char *p = names[n];
+       int dif;
+       const uchar *c1, *c2;
+       enum fnc_state state1 = fnc_DIR, state2 = fnc_DIR;
+
+       if (!f1 || !f1->basename) {
+               if (!f2 || !f2->basename)
+                       return 0;
+               return -1;
+       }
+       if (!f2 || !f2->basename)
+               return 1;
+
+       if (!(c1 = (uchar*)f1->dirname)) {
+               state1 = fnc_BASE;
+               c1 = (uchar*)f1->basename;
+       }
+       if (!(c2 = (uchar*)f2->dirname)) {
+               state2 = fnc_BASE;
+               c2 = (uchar*)f2->basename;
+       }
+
+       while (1) {
+               if ((dif = (int)*c1 - (int)*c2) != 0)
+                       break;
+               if (!*++c1) {
+                       switch (state1) {
+                       case fnc_DIR:
+                               state1 = fnc_SLASH;
+                               c1 = (uchar*)"/";
+                               break;
+                       case fnc_SLASH:
+                               state1 = fnc_BASE;
+                               c1 = (uchar*)f1->basename;
+                               break;
+                       case fnc_BASE:
+                               break;
+                       }
+               }
+               if (!*++c2) {
+                       switch (state2) {
+                       case fnc_DIR:
+                               state2 = fnc_SLASH;
+                               c2 = (uchar*)"/";
+                               break;
+                       case fnc_SLASH:
+                               state2 = fnc_BASE;
+                               c2 = (uchar*)f2->basename;
+                               break;
+                       case fnc_BASE:
+                               if (!*c1)
+                                       return 0;
+                               break;
+                       }
+               }
+       }
+
+       return dif;
+}
+
 
+/* Return a copy of the full filename of a flist entry, using the indicated
+ * buffer.
+ */
+char *f_name_to(struct file_struct *f, char *fbuf, int bsize)
+{
        if (!f || !f->basename)
                return NULL;
 
-       n = (n + 1) % 10;
-
        if (f->dirname) {
-               int off;
+               int off = strlcpy(fbuf, f->dirname, bsize);
+               off += strlcpy(fbuf + off, "/", bsize - off);
+               strlcpy(fbuf + off, f->basename, bsize - off);
+       } else
+               strlcpy(fbuf, f->basename, bsize);
+       return fbuf;
+}
 
-               off = strlcpy(p, f->dirname, MAXPATHLEN);
-               off += strlcpy(p + off, "/", MAXPATHLEN - off);
-               off += strlcpy(p + off, f->basename, MAXPATHLEN - off);
-       } else {
-               strlcpy(p, f->basename, MAXPATHLEN);
-       }
 
-       return p;
+/* Like f_name_to(), but we rotate through 5 static buffers of our own.
+ */
+char *f_name(struct file_struct *f)
+{
+       static char names[5][MAXPATHLEN];
+       static unsigned int n;
+
+       n = (n + 1) % (sizeof names / sizeof names[0]);
+
+       return f_name_to(f, names[n], sizeof names[0]);
 }