diff --git a/xorriso/iso_manip.c b/xorriso/iso_manip.c
index b9751a14..6aed3ae1 100644
--- a/xorriso/iso_manip.c
+++ b/xorriso/iso_manip.c
@@ -144,7 +144,7 @@ int Xorriso_graft_split(struct XorrisO *xorriso, IsoImage *volume,
                                 offset, xorriso->split_size,
                                 &part_node, 8);
    if(ret<=0)
-     return(0);
+     return(ret);
  }
  sprintf(xorriso->info_text, "Split into %d parts: %s",
          total_parts, Text_shellsafe(nominal_target, sfe, 0));
@@ -154,7 +154,9 @@ int Xorriso_graft_split(struct XorrisO *xorriso, IsoImage *volume,
 
 
 /* 
-   @param flag bit3= cut_out_node: offset and size are valid
+   @param flag bit0= ISO_NODE_NAME_NOT_UNIQUE exception mode:
+                     Do not issue message. Return existing node into *node.
+               bit3= cut_out_node: offset and size are valid
                bit8= hide in iso_rr
                bit9= hide in joliet
 */
@@ -226,14 +228,18 @@ int Xorriso_tree_graft_node(struct XorrisO *xorriso, IsoImage *volume,
 
 ex:;
  if(ret<0) {
-   Xorriso_process_msg_queues(xorriso,0);
-   if(ret == ISO_RR_NAME_TOO_LONG || ret == ISO_RR_NAME_RESERVED ||
-      ret == ISO_RR_PATH_TOO_LONG)
-     namept= nominal_target;
-   else
-     namept= nominal_source;
-   Xorriso_report_iso_error(xorriso, namept, ret,
-                            "Cannot add node to tree", 0, "FAILURE", 1|2);
+   if(ret == ISO_NODE_NAME_NOT_UNIQUE && (flag & 1)) {
+     iso_dir_get_node(dir, img_name, node);
+   } else {
+     Xorriso_process_msg_queues(xorriso,0);
+     if(ret == ISO_RR_NAME_TOO_LONG || ret == ISO_RR_NAME_RESERVED ||
+        ret == ISO_RR_PATH_TOO_LONG)
+       namept= nominal_target;
+     else
+       namept= nominal_source;
+     Xorriso_report_iso_error(xorriso, namept, ret,
+                              "Cannot add node to tree", 0, "FAILURE", 1|2);
+   }
    return(ret);
  }
  if(LIBISO_ISREG(*node))
@@ -242,6 +248,70 @@ ex:;
 }
 
 
+/*
+   @param boss_iter Opaque handle to be forwarded to actions in ISO image
+                    Set to NULL if calling this function without having
+                    a boss iterator objetc.
+   @param node      Pointer to pointer to existing node,
+                    *node is set to NULL, if the node gets removed.
+   @param flag bit0= source is directory
+               bit4= return 3 on rejection by exclusion or user
+               bit6= do not delete eventually existing node from di_array
+               bit7= no special handling of split file directories
+   @return     1= no action was needed, 2= target removed,
+               3= rejected with bit4, <=0 means error
+*/
+int Xoriso_handle_collision(struct XorrisO *xorriso, void *boss_iter,
+                            IsoNode **node, char *img_path,
+                            char *full_img_path, char *disk_path,
+                            char *show_path, int flag)
+{
+ int ret, target_is_dir, target_is_split, source_is_dir;
+
+ source_is_dir= flag & 1;
+ target_is_dir= LIBISO_ISDIR(*node);
+
+ target_is_split= 0;
+ if(target_is_dir && !(flag & 128))
+   target_is_split= Xorriso_is_split(xorriso, "", (void *) *node, 1 | 2);
+
+ if(!((target_is_dir && !target_is_split) && source_is_dir)) {
+   Xorriso_process_msg_queues(xorriso, 0);
+
+   /* handle overwrite situation */;
+   if(xorriso->do_overwrite == 1 ||
+      (xorriso->do_overwrite == 2 && !(target_is_dir && !target_is_split))) {
+     ret= Xorriso_rmi(xorriso, boss_iter, (off_t) 0, img_path,
+                      1 | 8 | (flag & 64));
+     if(ret <= 0)
+       return(ret);
+     if(ret == 3) {
+       sprintf(xorriso->info_text, "User revoked adding of: ");
+       Text_shellsafe(show_path, xorriso->info_text, 1);
+       Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "NOTE", 0);
+       return(3 * !!(flag & 16));
+     }
+     *node= NULL;
+     return(2);
+   }
+
+   if (disk_path[0])
+     Xorriso_msgs_submit(xorriso, 0, disk_path, 0, "ERRFILE", 0);
+   if(strcmp(full_img_path, img_path) == 0)
+     sprintf(xorriso->info_text,
+         "While grafting '%s' : file object exists and may not be overwritten",
+         img_path);
+   else
+     sprintf(xorriso->info_text,
+            "While grafting '%s' : '%s' exists and may not be overwritten",
+            full_img_path, img_path);
+   Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FAILURE", 0);
+   return(0);
+ }
+ return(1);
+}
+
+
 /* @param flag bit0= recursion is active
                bit1= do not report added files
                bit6= do not delete eventually existing node from di_array
@@ -255,8 +325,8 @@ int Xorriso_add_tree(struct XorrisO *xorriso, IsoDir *dir,
 {
  IsoImage *volume;
  IsoNode *node;
- int ret, target_is_dir, source_is_dir, source_is_link, fret, was_failure= 0;
- int do_not_dive, target_is_split= 0, hide_attrs;
+ int ret, source_is_dir, source_is_link, fret, was_failure= 0;
+ int do_not_dive, hide_attrs;
  struct DirseQ *dirseq= NULL;
  char *name, *img_name, *srcpt, *stbuf_src= "";
  struct stat stbuf, hstbuf;
@@ -265,6 +335,15 @@ int Xorriso_add_tree(struct XorrisO *xorriso, IsoDir *dir,
  char *sfe= NULL, *sfe2= NULL;
  char *disk_path= NULL, *img_path= NULL, *link_target= NULL;
 
+#define Xorriso_add_handle_collisioN 1
+#define Xorriso_optimistic_add_treE 1
+
+#ifndef Xorriso_optimistic_add_treE
+#ifndef Xorriso_add_handle_collisioN
+ int target_is_split= 0, target_is_dir;
+#endif
+#endif
+
  /* Avoiding large local memory objects in order to save stack space */
  sfe= malloc(5*SfileadrL);
  sfe2= malloc(5*SfileadrL);
@@ -404,6 +483,28 @@ cannot_lstat:;
        do_not_dive= 1;
    }
 
+#ifdef Xorriso_optimistic_add_treE
+
+   ret= Xorriso_tree_graft_node(xorriso, volume, dir, srcpt, img_name,
+                                "", img_path, (off_t) 0, (off_t) 0,
+                                &node, 1 | (hide_attrs << 8));
+   if(ret == ISO_NODE_NAME_NOT_UNIQUE) {
+     ret= Xoriso_handle_collision(xorriso, NULL, &node, img_path, img_path,
+                                  srcpt, img_path,
+                                  (!!source_is_dir) | (flag & (64 | 128)));
+     if(ret <= 0)
+       goto was_problem;
+     if(node == NULL) {
+       ret= Xorriso_tree_graft_node(xorriso, volume, dir, srcpt, img_name,
+                                    "", img_path, (off_t) 0, (off_t) 0,
+                                    &node, (hide_attrs << 8));
+       if(ret <= 0)
+         node= NULL;
+     }
+   }
+
+#else /* Xorriso_optimistic_add_treE */
+
    /* does a node exist with this name ? */
    node= NULL;
    if(dir != NULL) {
@@ -450,6 +551,9 @@ cannot_lstat:;
                                   "", img_path, (off_t) 0, (off_t) 0,
                                   &node, (hide_attrs << 8));
    }
+
+#endif /* Xorriso_optimistic_add_treE */
+
    if(node==NULL) {
      Xorriso_process_msg_queues(xorriso,0);
      Xorriso_msgs_submit(xorriso, 0, stbuf_src, 0, "ERRFILE", 0);
@@ -624,12 +728,21 @@ int Xorriso_graft_in(struct XorrisO *xorriso, void *boss_iter,
  IsoImage *volume;
  char path[SfileadrL], *apt, *npt, *cpt, sfe[5*SfileadrL], sfe2[5*SfileadrL];
  char *disk_path_pt, resolved_disk_path[SfileadrL];
- IsoDir *dir, *hdir;
+ IsoDir *dir= NULL, *hdir;
  IsoNode *node;
- int done= 0, is_dir= 0, l, ret, target_is_dir, source_is_dir, resolve_link= 0;
- int target_is_split, hide_attrs;
+ int done= 0, is_dir= 0, l, ret, source_is_dir, resolve_link= 0;
+ int hide_attrs;
  struct stat stbuf;
 
+#define Xorriso_graft_handle_collisioN 1
+#define Xorriso_optimistic_graft_iN 1
+
+#ifndef Xorriso_optimistic_graft_iN
+#ifndef Xorriso_graft_handle_collisioN
+ int target_is_split, target_is_dir;
+#endif
+#endif
+
  hide_attrs= (flag >> 8) & 3;
  if (disk_path == NULL && !(flag & 1)) {
    Xorriso_msgs_submit(xorriso, 0,
@@ -753,8 +866,136 @@ int Xorriso_graft_in(struct XorrisO *xorriso, void *boss_iter,
  continue;
    }
    source_is_dir= (is_dir || (flag&1) || !done);
-   ret= Xorriso_node_from_path(xorriso, volume, path, &node, 1);
+
+#ifdef Xorriso_optimistic_graft_iN
+
+   /* Directories of the source path are likely to exist already as directory
+      in the image.
+      That will cause two lookups with optimistic, and only one with
+      pessimistic.
+      So optimism will pay off only with the leaf. I.e. if(done).
+    */
+   if(source_is_dir) { /* eventually create directory */
+     ret= iso_dir_get_node(dir, apt, &node);
+     if(ret > 0) {
+       ret= Xoriso_handle_collision(xorriso, boss_iter, &node, path,
+                                    img_path, disk_path,
+                                    disk_path[0] ? disk_path : img_path,
+                               (!!source_is_dir) | (flag & (16 | 64 | 128)));
+       if(ret <= 0 || ret == 3)
+         return(ret);
+       if(ret == 1 && node != NULL)
+         dir= (IsoDir *) node;
+     } else
+       node= NULL;
+     if(node == NULL) {
+       ret= iso_tree_add_new_dir(dir, apt, &hdir);
+       if(ret < 0) {
+         Xorriso_process_msg_queues(xorriso,0);
+         if(disk_path[0])
+           Xorriso_msgs_submit(xorriso, 0, disk_path, 0, "ERRFILE", 0);
+         Xorriso_report_iso_error(xorriso, img_path, ret,
+                                  "Cannot create directory", 0, "FAILURE", 1);
+         sprintf(xorriso->info_text,
+               "While grafting '%s' : could not insert '%s'", img_path, path);
+         Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FAILURE", 0);
+         return(0);
+       }
+       if(xorriso->update_flags & 1) {
+         ret= Xorriso_mark_update_merge(xorriso, path, (IsoNode *) hdir, 1);
+         if(ret <= 0)
+           return(0);
+       }
+
+       dir= hdir;
+       Xorriso_set_change_pending(xorriso, 0);
+       iso_node_set_ctime((IsoNode *) dir, time(NULL));
+       iso_node_set_uid((IsoNode *) dir, geteuid());
+       iso_node_set_gid((IsoNode *) dir, getegid());
+
+       if(disk_path[0] && !done) {
+         /* This not only copies disk directory properties
+            but also sets eventual hide_attrs */
+         Xorriso_copy_implicit_properties(xorriso, dir, img_path, path,
+                                          disk_path, !!(flag&8));
+       }
+     }
+   }
+
+   if(done) {
+attach_source:;
+     if(flag&1) {
+       /* directory node was created above */;
+
+     } else if(is_dir) {
+       Xorriso_transfer_properties(xorriso, &stbuf, disk_path,
+                                   (IsoNode *) dir, 4 | 32);
+       if(!(flag&32)) {
+         ret= Xorriso_add_tree(xorriso, dir, img_path, disk_path, NULL,
+                               flag & (2 | 64 | 128));
+         if(ret<=0)
+           return(ret);
+       }
+     } else {
+       if(resolve_link) {
+         ret= Xorriso_resolve_link(xorriso, disk_path, resolved_disk_path, 0);
+         if(ret<=0)
+           return(ret);
+         disk_path_pt= resolved_disk_path;
+       } else
+         disk_path_pt= disk_path;
+
+       ret= Xorriso_tree_graft_node(xorriso, volume, dir, disk_path_pt, apt,
+                                    disk_path, img_path, offset, cut_size,
+                                    &node, 1 | (flag & 8) | (hide_attrs << 8));
+       if(ret == ISO_NODE_NAME_NOT_UNIQUE) {
+         ret= Xoriso_handle_collision(xorriso, boss_iter, &node, img_path,
+                                      img_path, disk_path,
+                                      disk_path[0] ? disk_path : img_path,
+                                      (flag & (16 | 64 | 128)));
+         if(ret <= 0 || ret == 3)
+           return(ret);
+         ret= Xorriso_tree_graft_node(xorriso, volume, dir, disk_path_pt, apt,
+                                      disk_path, img_path, offset, cut_size,
+                                      &node, (flag & 8) | (hide_attrs << 8));
+       }
+       if(ret<=0) {
+         sprintf(xorriso->info_text, "Grafting failed:  %s = %s",
+             Text_shellsafe(img_path,sfe,0), Text_shellsafe(disk_path,sfe2,0));
+         Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FAILURE", 0);
+         return(0);
+       }
+       Xorriso_set_change_pending(xorriso, 0);
+       iso_node_set_name(node, apt);
+
+       xorriso->pacifier_count++;
+       if(xorriso->pacifier_count%100 && !(flag&2))
+         Xorriso_pacifier_callback(xorriso, "files added",
+                                   xorriso->pacifier_count,
+                                   xorriso->pacifier_total, "", 0);
+     }
+   } else
+     *npt= '/';
+
+#else /* Xorriso_optimistic_graft_iN */
+
+   node= NULL;
+   ret= iso_dir_get_node(dir, apt, &node);
    if(ret>0) {
+
+#ifdef Xorriso_graft_handle_collisioN
+
+     ret= Xoriso_handle_collision(xorriso, boss_iter, &node, path, img_path,
+                                  disk_path,
+                                  disk_path[0] ? disk_path : img_path,
+                                 (!!source_is_dir) | (flag & (16 | 64 | 128)));
+     if(ret <= 0 || ret == 3)
+       return(ret);
+     if(ret == 2)
+       goto handle_path_node;
+
+#else /* Xorriso_graft_handle_collisioN */
+
      target_is_dir= LIBISO_ISDIR(node);
 
      target_is_split= 0;
@@ -790,6 +1031,9 @@ int Xorriso_graft_in(struct XorrisO *xorriso, void *boss_iter,
        Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FAILURE", 0);
        return(0);
      }
+
+#endif /* ! Xorriso_graft_handle_collisioN */
+
      dir= (IsoDir *) node;
    }
 
@@ -868,7 +1112,11 @@ attach_source:;
      }
    } else
      *npt= '/';
+
+#endif /* ! Xorriso_optimistic_graft_iN */
+
  }
+
  Xorriso_process_msg_queues(xorriso,0);
  return(1+!!is_dir);
 }
diff --git a/xorriso/xorriso_timestamp.h b/xorriso/xorriso_timestamp.h
index e966a10b..6255173f 100644
--- a/xorriso/xorriso_timestamp.h
+++ b/xorriso/xorriso_timestamp.h
@@ -1 +1 @@
-#define Xorriso_timestamP "2011.04.27.150829"
+#define Xorriso_timestamP "2011.04.30.121138"