text: /*
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
  
  /** \file
   * \ingroup bli
   */
  
  /* TODO,
   * currently there are some cases we don't support.
   * - passing output paths to the visitor?, like render out.
   * - passing sequence strips with many images.
   * - passing directory paths - visitors don't know which path is a dir or a file.
   * */
  
  #include <sys/stat.h>
  
  #include <assert.h>
  #include <string.h>
  
  /* path/file handling stuff */
  #ifndef WIN32
  #  include <dirent.h>
  #  include <unistd.h>
  #else
  #  include "BLI_winstuff.h"
  #  include <io.h>
  #endif
  
  #include "MEM_guardedalloc.h"
  
  #include "DNA_brush_types.h"
  #include "DNA_cachefile_types.h"
  #include "DNA_fluid_types.h"
  #include "DNA_freestyle_types.h"
  #include "DNA_image_types.h"
  #include "DNA_material_types.h"
  #include "DNA_mesh_types.h"
  #include "DNA_modifier_types.h"
  #include "DNA_movieclip_types.h"
  #include "DNA_node_types.h"
  #include "DNA_object_fluidsim_types.h"
  #include "DNA_object_force_types.h"
  #include "DNA_object_types.h"
  #include "DNA_particle_types.h"
  #include "DNA_scene_types.h"
  #include "DNA_sequence_types.h"
  #include "DNA_sound_types.h"
  #include "DNA_text_types.h"
  #include "DNA_texture_types.h"
  #include "DNA_vfont_types.h"
  #include "DNA_volume_types.h"
  
  #include "BLI_blenlib.h"
  #include "BLI_utildefines.h"
  
  #include "BKE_font.h"
  #include "BKE_image.h"
  #include "BKE_lib_id.h"
  #include "BKE_library.h"
  #include "BKE_main.h"
  #include "BKE_node.h"
  #include "BKE_report.h"
  #include "BKE_sequencer.h"
  
  #include "BKE_bpath.h" /* own include */
  
  #include "CLG_log.h"
  
  #ifndef _MSC_VER
  #  include "BLI_strict_flags.h"
  #endif
  
  static CLG_LogRef LOG = {"bke.bpath"};
  
  /* -------------------------------------------------------------------- */
  /** \name Check Missing Files
   * \{ */
  
  static bool checkMissingFiles_visit_cb(void *userdata,
                                         char *UNUSED(path_dst),
                                         const char *path_src)
  {
    ReportList *reports = (ReportList *)userdata;
  
    if (!BLI_exists(path_src)) {
      BKE_reportf(reports, RPT_WARNING, "Path '%s' not found", path_src);
    }
  
    return false;
  }
  
  /* high level function */
  void BKE_bpath_missing_files_check(Main *bmain, ReportList *reports)
  {
    BKE_bpath_traverse_main(bmain,
                            checkMissingFiles_visit_cb,
                            BKE_BPATH_TRAVERSE_ABS | BKE_BPATH_TRAVERSE_SKIP_PACKED,
                            reports);
  }
  
  /** \} */
  
  /* -------------------------------------------------------------------- */
  /** \name Rebase Relative Paths
   * \{ */
  
  typedef struct BPathRebase_Data {
    const char *basedir_src;
    const char *basedir_dst;
    ReportList *reports;
  
    int count_tot;
    int count_changed;
    int count_failed;
  } BPathRebase_Data;
  
  static bool bpath_relative_rebase_visit_cb(void *userdata, char *path_dst, const char *path_src)
  {
    BPathRebase_Data *data = (BPathRebase_Data *)userdata;
  
    data->count_tot++;
  
    if (BLI_path_is_rel(path_src)) {
      char filepath[(FILE_MAXDIR * 2) + FILE_MAXFILE];
      BLI_strncpy(filepath, path_src, FILE_MAX);
      if (BLI_path_abs(filepath, data->basedir_src)) {
        BLI_path_normalize(NULL, filepath);
  
        /* This may fail, if so it's fine to leave absolute since the path is still valid. */
        BLI_path_rel(filepath, data->basedir_dst);
  
        BLI_strncpy(path_dst, filepath, FILE_MAX);
        data->count_changed++;
        return true;
      }
      else {
        /* Failed to make relative path absolute. */
        BLI_assert(0);
        BKE_reportf(data->reports, RPT_WARNING, "Path '%s' cannot be made absolute", path_src);
        data->count_failed++;
        return false;
      }
      return false;
    }
    else {
      /* Absolute, leave this as-is. */
      return false;
    }
  }
  
  void BKE_bpath_relative_rebase(Main *bmain,
                                 const char *basedir_src,
                                 const char *basedir_dst,
                                 ReportList *reports)
  {
    BPathRebase_Data data = {NULL};
    const int flag = BKE_BPATH_TRAVERSE_SKIP_LIBRARY;
  
    BLI_assert(basedir_src[0] != '\0');
    BLI_assert(basedir_dst[0] != '\0');
  
    data.basedir_src = basedir_src;
    data.basedir_dst = basedir_dst;
    data.reports = reports;
  
    BKE_bpath_traverse_main(bmain, bpath_relative_rebase_visit_cb, flag, (void *)&data);
  
    BKE_reportf(reports,
                data.count_failed ? RPT_WARNING : RPT_INFO,
                "Total files %d | Changed %d | Failed %d",
                data.count_tot,
                data.count_changed,
                data.count_failed);
  }
  
  /** \} */
  
  /* -------------------------------------------------------------------- */
  /** \name Make Paths Relative
   * \{ */
  
  typedef struct BPathRemap_Data {
    const char *basedir;
    ReportList *reports;
  
    int count_tot;
    int count_changed;
    int count_failed;
  } BPathRemap_Data;
  
  static bool bpath_relative_convert_visit_cb(void *userdata, char *path_dst, const char *path_src)
  {
    BPathRemap_Data *data = (BPathRemap_Data *)userdata;
  
    data->count_tot++;
  
    if (BLI_path_is_rel(path_src)) {
      return false; /* already relative */
    }
    else {
      strcpy(path_dst, path_src);
      BLI_path_rel(path_dst, data->basedir);
      if (BLI_path_is_rel(path_dst)) {
        data->count_changed++;
      }
      else {
        BKE_reportf(data->reports, RPT_WARNING, "Path '%s' cannot be made relative", path_src);
        data->count_failed++;
      }
      return true;
    }
  }
  
  void BKE_bpath_relative_convert(Main *bmain, const char *basedir, ReportList *reports)
  {
    BPathRemap_Data data = {NULL};
    const int flag = BKE_BPATH_TRAVERSE_SKIP_LIBRARY;
  
    if (basedir[0] == '\0') {
      CLOG_ERROR(&LOG, "basedir='', this is a bug");
      return;
    }
  
    data.basedir = basedir;
    data.reports = reports;
  
    BKE_bpath_traverse_main(bmain, bpath_relative_convert_visit_cb, flag, (void *)&data);
  
    BKE_reportf(reports,
                data.count_failed ? RPT_WARNING : RPT_INFO,
                "Total files %d | Changed %d | Failed %d",
                data.count_tot,
                data.count_changed,
                data.count_failed);
  }
  
  /** \} */
  
  /* -------------------------------------------------------------------- */
  /** \name Make Paths Absolute
   * \{ */
  
  static bool bpath_absolute_convert_visit_cb(void *userdata, char *path_dst, const char *path_src)
  {
    BPathRemap_Data *data = (BPathRemap_Data *)userdata;
  
    data->count_tot++;
  
    if (BLI_path_is_rel(path_src) == false) {
      return false; /* already absolute */
    }
    else {
      strcpy(path_dst, path_src);
      BLI_path_abs(path_dst, data->basedir);
      if (BLI_path_is_rel(path_dst) == false) {
        data->count_changed++;
      }
      else {
        BKE_reportf(data->reports, RPT_WARNING, "Path '%s' cannot be made absolute", path_src);
        data->count_failed++;
      }
      return true;
    }
  }
  
  /* similar to BKE_bpath_relative_convert - keep in sync! */
  void BKE_bpath_absolute_convert(Main *bmain, const char *basedir, ReportList *reports)
  {
    BPathRemap_Data data = {NULL};
    const int flag = BKE_BPATH_TRAVERSE_SKIP_LIBRARY;
  
    if (basedir[0] == '\0') {
      CLOG_ERROR(&LOG, "basedir='', this is a bug");
      return;
    }
  
    data.basedir = basedir;
    data.reports = reports;
  
    BKE_bpath_traverse_main(bmain, bpath_absolute_convert_visit_cb, flag, (void *)&data);
  
    BKE_reportf(reports,
                data.count_failed ? RPT_WARNING : RPT_INFO,
                "Total files %d | Changed %d | Failed %d",
                data.count_tot,
                data.count_changed,
                data.count_failed);
  }
  
  /** \} */
  
  /* -------------------------------------------------------------------- */
  /** \name Find Missing Files
   * \{ */
  
  /**
   * find this file recursively, use the biggest file so thumbnails don't get used by mistake
   * \param filename_new: the path will be copied here, caller must initialize as empty string.
   * \param dirname: subdir to search
   * \param filename: set this filename
   * \param filesize: filesize for the file
   *
   * \returns found: 1/0.
   */
  #define MAX_RECUR 16
  static bool missing_files_find__recursive(char *filename_new,
                                            const char *dirname,
                                            const char *filename,
                                            int64_t *r_filesize,
                                            int *r_recur_depth)
  {
    /* file searching stuff */
    DIR *dir;
    struct dirent *de;
    BLI_stat_t status;
    char path[FILE_MAX];
    int64_t size;
    bool found = false;
  
    dir = opendir(dirname);
  
    if (dir == NULL) {
      return found;
    }
  
    if (*r_filesize == -1) {
      *r_filesize = 0; /* dir opened fine */
    }
  
    while ((de = readdir(dir)) != NULL) {
  
      if (FILENAME_IS_CURRPAR(de->d_name)) {
        continue;
      }
  
      BLI_join_dirfile(path, sizeof(path), dirname, de->d_name);
  
      if (BLI_stat(path, &status) == -1) {
        continue; /* cant stat, don't bother with this file, could print debug info here */
      }
  
      if (S_ISREG(status.st_mode)) {                              /* is file */
        if (BLI_path_ncmp(filename, de->d_name, FILE_MAX) == 0) { /* name matches */
          /* open the file to read its size */
          size = status.st_size;
          if ((size > 0) && (size > *r_filesize)) { /* find the biggest file */
            *r_filesize = size;
            BLI_strncpy(filename_new, path, FILE_MAX);
            found = true;
          }
        }
      }
      else if (S_ISDIR(status.st_mode)) { /* is subdir */
        if (*r_recur_depth <= MAX_RECUR) {
          (*r_recur_depth)++;
          found |= missing_files_find__recursive(
              filename_new, path, filename, r_filesize, r_recur_depth);
          (*r_recur_depth)--;
        }
      }
    }
    closedir(dir);
    return found;
  }
  
  typedef struct BPathFind_Data {
    const char *basedir;
    const char *searchdir;
    ReportList *reports;
    bool find_all;
  } BPathFind_Data;
  
  static bool missing_files_find__visit_cb(void *userdata, char *path_dst, const char *path_src)
  {
    BPathFind_Data *data = (BPathFind_Data *)userdata;
    char filename_new[FILE_MAX];
  
    int64_t filesize = -1;
    int recur_depth = 0;
    bool found;
  
    if (data->find_all == false) {
      if (BLI_exists(path_src)) {
        return false;
      }
    }
  
    filename_new[0] = '\0';
  
    found = missing_files_find__recursive(
        filename_new, data->searchdir, BLI_path_basename(path_src), &filesize, &recur_depth);
  
    if (filesize == -1) { /* could not open dir */
      BKE_reportf(data->reports,
                  RPT_WARNING,
                  "Could not open directory '%s'",
                  BLI_path_basename(data->searchdir));
      return false;
    }
    else if (found == false) {
      BKE_reportf(data->reports,
                  RPT_WARNING,
                  "Could not find '%s' in '%s'",
                  BLI_path_basename(path_src),
                  data->searchdir);
      return false;
    }
    else {
      bool was_relative = BLI_path_is_rel(path_dst);
  
      BLI_strncpy(path_dst, filename_new, FILE_MAX);
  
      /* keep path relative if the previous one was relative */
      if (was_relative) {
        BLI_path_rel(path_dst, data->basedir);
      }
  
      return true;
    }
  }
  
  void BKE_bpath_missing_files_find(Main *bmain,
                                    const char *searchpath,
                                    ReportList *reports,
                                    const bool find_all)
  {
    struct BPathFind_Data data = {NULL};
    const int flag = BKE_BPATH_TRAVERSE_ABS | BKE_BPATH_TRAVERSE_RELOAD_EDITED;
  
    data.basedir = BKE_main_blendfile_path(bmain);
    data.reports = reports;
    data.searchdir = searchpath;
    data.find_all = find_all;
  
    BKE_bpath_traverse_main(bmain, missing_files_find__visit_cb, flag, (void *)&data);
  }
  
  /** \} */
  
  /* -------------------------------------------------------------------- */
  /** \name Generic File Path Traversal API
   * \{ */
  
  /**
   * Run a visitor on a string, replacing the contents of the string as needed.
   */
  static bool rewrite_path_fixed(char *path,
                                 BPathVisitor visit_cb,
                                 const char *absbase,
                                 void *userdata)
  {
    char path_src_buf[FILE_MAX];
    const char *path_src;
    char path_dst[FILE_MAX];
  
    if (absbase) {
      BLI_strncpy(path_src_buf, path, sizeof(path_src_buf));
      BLI_path_abs(path_src_buf, absbase);
      path_src = path_src_buf;
    }
    else {
      path_src = path;
    }
  
    /* so functions can check old value */
    BLI_strncpy(path_dst, path, FILE_MAX);
  
    if (visit_cb(userdata, path_dst, path_src)) {
      BLI_strncpy(path, path_dst, FILE_MAX);
      return true;
    }
    else {
      return false;
    }
  }
  
  static bool rewrite_path_fixed_dirfile(char path_dir[FILE_MAXDIR],
                                         char path_file[FILE_MAXFILE],
                                         BPathVisitor visit_cb,
                                         const char *absbase,
                                         void *userdata)
  {
    char path_src[FILE_MAX];
    char path_dst[FILE_MAX];
  
    BLI_join_dirfile(path_src, sizeof(path_src), path_dir, path_file);
  
    /* so functions can check old value */
    BLI_strncpy(path_dst, path_src, FILE_MAX);
  
    if (absbase) {
      BLI_path_abs(path_src, absbase);
    }
  
    if (visit_cb(userdata, path_dst, (const char *)path_src)) {
      BLI_split_dirfile(path_dst, path_dir, path_file, FILE_MAXDIR, FILE_MAXFILE);
      return true;
    }
    else {
      return false;
    }
  }
  
  static bool rewrite_path_alloc(char **path,
                                 BPathVisitor visit_cb,
                                 const char *absbase,
                                 void *userdata)
  {
    char path_src_buf[FILE_MAX];
    const char *path_src;
    char path_dst[FILE_MAX];
  
    if (absbase) {
      BLI_strncpy(path_src_buf, *path, sizeof(path_src_buf));
      BLI_path_abs(path_src_buf, absbase);
      path_src = path_src_buf;
    }
    else {
      path_src = *path;
    }
  
    if (visit_cb(userdata, path_dst, path_src)) {
      MEM_freeN(*path);
      (*path) = BLI_strdup(path_dst);
      return true;
    }
    else {
      return false;
    }
  }
  
  /**
   * Run visitor function 'visit' on all paths contained in 'id'.
   */
  void BKE_bpath_traverse_id(
      Main *bmain, ID *id, BPathVisitor visit_cb, const int flag, void *bpath_user_data)
  {
    const char *absbase = (flag & BKE_BPATH_TRAVERSE_ABS) ? ID_BLEND_PATH(bmain, id) : NULL;
  
    if ((flag & BKE_BPATH_TRAVERSE_SKIP_LIBRARY) && ID_IS_LINKED(id)) {
      return;
    }
  
    switch (GS(id->name)) {
      case ID_IM: {
        Image *ima;
        ima = (Image *)id;
        if (BKE_image_has_packedfile(ima) == false || (flag & BKE_BPATH_TRAVERSE_SKIP_PACKED) == 0) {
          /* Skip empty file paths, these are typically from generated images and
           * don't make sense to add directories to until the image has been saved
           * once to give it a meaningful value. */
          if (ELEM(ima->source, IMA_SRC_FILE, IMA_SRC_MOVIE, IMA_SRC_SEQUENCE, IMA_SRC_TILED) &&
              ima->name[0]) {
            if (rewrite_path_fixed(ima->name, visit_cb, absbase, bpath_user_data)) {
              if (flag & BKE_BPATH_TRAVERSE_RELOAD_EDITED) {
                if (!BKE_image_has_packedfile(ima) &&
                    /* image may have been painted onto (and not saved, T44543) */
                    !BKE_image_is_dirty(ima)) {
                  BKE_image_signal(bmain, ima, NULL, IMA_SIGNAL_RELOAD);
                }
              }
            }
          }
        }
        break;
      }
      case ID_BR: {
        Brush *brush = (Brush *)id;
        if (brush->icon_filepath[0]) {
          rewrite_path_fixed(brush->icon_filepath, visit_cb, absbase, bpath_user_data);
        }
        break;
      }
      case ID_OB: {
        Object *ob = (Object *)id;
        ModifierData *md;
        ParticleSystem *psys;
  
  #define BPATH_TRAVERSE_POINTCACHE(ptcaches) \
    { \
      PointCache *cache; \
      for (cache = (ptcaches).first; cache; cache = cache->next) { \
        if (cache->flag & PTCACHE_DISK_CACHE) { \
          rewrite_path_fixed(cache->path, visit_cb, absbase, bpath_user_data); \
        } \
      } \
    } \
    (void)0
  
        for (md = ob->modifiers.first; md; md = md->next) {
          if (md->type == eModifierType_Fluidsim) {
            FluidsimModifierData *fluidmd = (FluidsimModifierData *)md;
            if (fluidmd->fss) {
              rewrite_path_fixed(fluidmd->fss->surfdataPath, visit_cb, absbase, bpath_user_data);
            }
          }
          else if (md->type == eModifierType_Fluid) {
            FluidModifierData *mmd = (FluidModifierData *)md;
            if (mmd->type & MOD_FLUID_TYPE_DOMAIN && mmd->domain) {
              rewrite_path_fixed(mmd->domain->cache_directory, visit_cb, absbase, bpath_user_data);
            }
          }
          else if (md->type == eModifierType_Cloth) {
            ClothModifierData *clmd = (ClothModifierData *)md;
            BPATH_TRAVERSE_POINTCACHE(clmd->ptcaches);
          }
          else if (md->type == eModifierType_Ocean) {
            OceanModifierData *omd = (OceanModifierData *)md;
            rewrite_path_fixed(omd->cachepath, visit_cb, absbase, bpath_user_data);
          }
          else if (md->type == eModifierType_MeshCache) {
            MeshCacheModifierData *mcmd = (MeshCacheModifierData *)md;
            rewrite_path_fixed(mcmd->filepath, visit_cb, absbase, bpath_user_data);
          }
        }
  
        if (ob->soft) {
          BPATH_TRAVERSE_POINTCACHE(ob->soft->shared->ptcaches);
        }
  
        for (psys = ob->particlesystem.first; psys; psys = psys->next) {
          BPATH_TRAVERSE_POINTCACHE(psys->ptcaches);
        }
  
  #undef BPATH_TRAVERSE_POINTCACHE
  
        break;
      }
      case ID_SO: {
        bSound *sound = (bSound *)id;
        if (sound->packedfile == NULL || (flag & BKE_BPATH_TRAVERSE_SKIP_PACKED) == 0) {
          rewrite_path_fixed(sound->name, visit_cb, absbase, bpath_user_data);
        }
        break;
      }
      case ID_VO: {
        Volume *volume = (Volume *)id;
        if (volume->packedfile == NULL || (flag & BKE_BPATH_TRAVERSE_SKIP_PACKED) == 0) {
          rewrite_path_fixed(volume->filepath, visit_cb, absbase, bpath_user_data);
        }
        break;
      }
      case ID_TXT:
        if (((Text *)id)->name) {
          rewrite_path_alloc(&((Text *)id)->name, visit_cb, absbase, bpath_user_data);
        }
        break;
      case ID_VF: {
        VFont *vfont = (VFont *)id;
        if (vfont->packedfile == NULL || (flag & BKE_BPATH_TRAVERSE_SKIP_PACKED) == 0) {
          if (BKE_vfont_is_builtin(vfont) == false) {
            rewrite_path_fixed(((VFont *)id)->name, visit_cb, absbase, bpath_user_data);
          }
        }
        break;
      }
      case ID_MA: {
        Material *ma = (Material *)id;
        bNodeTree *ntree = ma->nodetree;
  
        if (ntree) {
          bNode *node;
  
          for (node = ntree->nodes.first; node; node = node->next) {
            if (node->type == SH_NODE_SCRIPT) {
              NodeShaderScript *nss = (NodeShaderScript *)node->storage;
              rewrite_path_fixed(nss->filepath, visit_cb, absbase, bpath_user_data);
            }
            else if (node->type == SH_NODE_TEX_IES) {
              NodeShaderTexIES *ies = (NodeShaderTexIES *)node->storage;
              rewrite_path_fixed(ies->filepath, visit_cb, absbase, bpath_user_data);
            }
          }
        }
        break;
      }
      case ID_NT: {
        bNodeTree *ntree = (bNodeTree *)id;
        bNode *node;
  
        if (ntree->type == NTREE_SHADER) {
          /* same as lines above */
          for (node = ntree->nodes.first; node; node = node->next) {
            if (node->type == SH_NODE_SCRIPT) {
              NodeShaderScript *nss = (NodeShaderScript *)node->storage;
              rewrite_path_fixed(nss->filepath, visit_cb, absbase, bpath_user_data);
            }
            else if (node->type == SH_NODE_TEX_IES) {
              NodeShaderTexIES *ies = (NodeShaderTexIES *)node->storage;
              rewrite_path_fixed(ies->filepath, visit_cb, absbase, bpath_user_data);
            }
          }
        }
        break;
      }
      case ID_SCE: {
        Scene *scene = (Scene *)id;
        if (scene->ed) {
          Sequence *seq;
  
          SEQ_BEGIN (scene->ed, seq) {
            if (SEQ_HAS_PATH(seq)) {
              StripElem *se = seq->strip->stripdata;
  
              if (ELEM(seq->type, SEQ_TYPE_MOVIE, SEQ_TYPE_SOUND_RAM) && se) {
                rewrite_path_fixed_dirfile(
                    seq->strip->dir, se->name, visit_cb, absbase, bpath_user_data);
              }
              else if ((seq->type == SEQ_TYPE_IMAGE) && se) {
                /* might want an option not to loop over all strips */
                unsigned int len = (unsigned int)MEM_allocN_len(se) / (unsigned int)sizeof(*se);
                unsigned int i;
  
                if (flag & BKE_BPATH_TRAVERSE_SKIP_MULTIFILE) {
                  /* only operate on one path */
                  len = MIN2(1u, len);
                }
  
                for (i = 0; i < len; i++, se++) {
                  rewrite_path_fixed_dirfile(
                      seq->strip->dir, se->name, visit_cb, absbase, bpath_user_data);
                }
              }
              else {
                /* simple case */
                rewrite_path_fixed(seq->strip->dir, visit_cb, absbase, bpath_user_data);
              }
            }
          }
          SEQ_END;
        }
        break;
      }
      case ID_ME: {
        Mesh *me = (Mesh *)id;
        if (me->ldata.external) {
          rewrite_path_fixed(me->ldata.external->filename, visit_cb, absbase, bpath_user_data);
        }
        break;
      }
      case ID_LI: {
        Library *lib = (Library *)id;
        /* keep packedfile paths always relative to the blend */
        if (lib->packedfile == NULL) {
          if (rewrite_path_fixed(lib->name, visit_cb, absbase, bpath_user_data)) {
            BKE_library_filepath_set(bmain, lib, lib->name);
          }
        }
        break;
      }
      case ID_MC: {
        MovieClip *clip = (MovieClip *)id;
        rewrite_path_fixed(clip->name, visit_cb, absbase, bpath_user_data);
        break;
      }
      case ID_CF: {
        CacheFile *cache_file = (CacheFile *)id;
        rewrite_path_fixed(cache_file->filepath, visit_cb, absbase, bpath_user_data);
        break;
      }
      default:
        /* Nothing to do for other IDs that don't contain file paths. */
        break;
    }
  }
  
  void BKE_bpath_traverse_id_list(
      Main *bmain, ListBase *lb, BPathVisitor visit_cb, const int flag, void *bpath_user_data)
  {
    ID *id;
    for (id = lb->first; id; id = id->next) {
      BKE_bpath_traverse_id(bmain, id, visit_cb, flag, bpath_user_data);
    }
  }
  
  void BKE_bpath_traverse_main(Main *bmain,
                               BPathVisitor visit_cb,
                               const int flag,
                               void *bpath_user_data)
  {
    ListBase *lbarray[MAX_LIBARRAY];
    int a = set_listbasepointers(bmain, lbarray);
    while (a--) {
      BKE_bpath_traverse_id_list(bmain, lbarray[a], visit_cb, flag, bpath_user_data);
    }
  }
  
  /**
   * Rewrites a relative path to be relative to the main file - unless the path is
   * absolute, in which case it is not altered.
   */
  bool BKE_bpath_relocate_visitor(void *pathbase_v, char *path_dst, const char *path_src)
  {
    /* be sure there is low chance of the path being too short */
    char filepath[(FILE_MAXDIR * 2) + FILE_MAXFILE];
    const char *base_new = ((char **)pathbase_v)[0];
    const char *base_old = ((char **)pathbase_v)[1];
  
    if (BLI_path_is_rel(base_old)) {
      CLOG_ERROR(&LOG, "old base path '%s' is not absolute.", base_old);
      return false;
    }
  
    /* Make referenced file absolute. This would be a side-effect of
     * BLI_path_normalize, but we do it explicitly so we know if it changed. */
    BLI_strncpy(filepath, path_src, FILE_MAX);
    if (BLI_path_abs(filepath, base_old)) {
      /* Path was relative and is now absolute. Remap.
       * Important BLI_path_normalize runs before the path is made relative
       * because it wont work for paths that start with "//../" */
      BLI_path_normalize(base_new, filepath);
      BLI_path_rel(filepath, base_new);
      BLI_strncpy(path_dst, filepath, FILE_MAX);
      return true;
    }
    else {
      /* Path was not relative to begin with. */
      return false;
    }
  }
  
  /** \} */
  
  /* -------------------------------------------------------------------- */
  /** \name Backup/Restore/Free functions,
   *
   * \note These functions assume the data won't change order.
   * \{ */
  
  struct PathStore {
    struct PathStore *next, *prev;
  };
  
  static bool bpath_list_append(void *userdata, char *UNUSED(path_dst), const char *path_src)
  {
    /* store the path and string in a single alloc */
    ListBase *ls = userdata;
    size_t path_size = strlen(path_src) + 1;
    struct PathStore *path_store = MEM_mallocN(sizeof(struct PathStore) + path_size, __func__);
    char *filepath = (char *)(path_store + 1);
  
    memcpy(filepath, path_src, path_size);
    BLI_addtail(ls, path_store);
    return false;
  }
  
  static bool bpath_list_restore(void *userdata, char *path_dst, const char *path_src)
  {
    /* assume ls->first wont be NULL because the number of paths can't change!
     * (if they do caller is wrong) */
    ListBase *ls = userdata;
    struct PathStore *path_store = ls->first;
    const char *filepath = (char *)(path_store + 1);
    bool ret;
  
    if (STREQ(path_src, filepath)) {
      ret = false;
    }
    else {
      BLI_strncpy(path_dst, filepath, FILE_MAX);
      ret = true;
    }
  
    BLI_freelinkN(ls, path_store);
    return ret;
  }
  
  /* return ls_handle */
  void *BKE_bpath_list_backup(Main *bmain, const int flag)
  {
    ListBase *ls = MEM_callocN(sizeof(ListBase), __func__);
  
    BKE_bpath_traverse_main(bmain, bpath_list_append, flag, ls);
  
    return ls;
  }
  
  void BKE_bpath_list_restore(Main *bmain, const int flag, void *ls_handle)
  {
    ListBase *ls = ls_handle;
  
    BKE_bpath_traverse_main(bmain, bpath_list_restore, flag, ls);
  }
  
  void BKE_bpath_list_free(void *ls_handle)
  {
    ListBase *ls = ls_handle;
    BLI_assert(BLI_listbase_is_empty(ls)); /* assumes we were used */
    BLI_freelistN(ls);
    MEM_freeN(ls);
  }
  
  /** \} */
  