server: recycle stale temporary directory handles

Novell NCOPY can allocate temporary directory handles while checking
effective directory rights before copying.  On long-running test runs the
temporary directory handle table may already contain stale entries, causing
Allocate Temporary Directory Handle to fail with -0x9d / "no directory
handles".  NCOPY then falls back to relative GetEffectiveRights requests that
fail and reports:

    NWGetEffectiveDirectoryRights returned an error.

Restore recycling of stale temporary directory handles in xinsert_new_dir().
Free slots are still preferred.  If none are available and the caller requests
a temporary handle, recycle the oldest temporary handle for the same task first,
then the oldest temporary handle globally.  Permanent directory handles are not
recycled.

This matches the expected NetWare-style behaviour for temporary handles and
allows NCOPY-style allocate-temp-handle / get-effective-rights flows to keep
working after repeated tests.

src/connect.c

@@ -2485,26 +2485,55 @@ int xinsert_new_dir(int volume, uint8 *path, int dev, int inode, int drive, int
 {
   int j              = 0;
   int    freehandle  = 0;
-#if 0
-  time_t lowtime     = time(NULL);
-  int    timedhandle = 0;
-#endif
-  /* first look, whether drive is allready in use */
+  int    timedhandle_same_task = 0;
+  int    timedhandle_any_task  = 0;
+  time_t lowtime_same_task = time(NULL);
+  time_t lowtime_any_task  = time(NULL);
+
+  /*
+   * Temporary directory handles are supposed to be freed automatically at
+   * End Of Job.  Some DOS requesters/tools, notably Novell NCOPY through
+   * Client32, can allocate temp handles without sending EOJ often enough for
+   * MARS-NWE's small dir-handle table.  The old code only reused empty slots
+   * and returned 0x9d (no directory handles) once the table had filled with
+   * stale temp handles.  That makes NCOPY fail before the actual copy with
+   * "NWGetEffectiveDirectoryRights returned an error."
+   *
+   * Prefer a genuinely free slot.  If the table is full and this is another
+   * temp-handle allocation, recycle the oldest temp handle from the same task;
+   * only if none exists, recycle the oldest temp handle from any task.
+   * Permanent handles are never recycled here.
+   */
   for (j = (used_dirs) ? 1 : 0; j < (int)used_dirs; j++) {
     NW_DIR *d = &(dirs[j]);
-    if (!d->inode)
+    if (!d->inode) {
        freehandle = j+1;
-#if 0
-    } else if (d->is_temp && d->timestamp < lowtime) {
-      timedhandle = j+1;
-      lowtime     = d->timestamp;
+    } else if (is_temp && d->is_temp) {
+      if (d->task == (uint8)task && d->timestamp <= lowtime_same_task) {
+        timedhandle_same_task = j+1;
+        lowtime_same_task     = d->timestamp;
+      }
+      if (d->timestamp <= lowtime_any_task) {
+        timedhandle_any_task = j+1;
+        lowtime_any_task     = d->timestamp;
+      }
     }
-#endif
   }
   if (!freehandle && used_dirs < MAX_NW_DIRS) freehandle = ++used_dirs;
-#if 0
-  if (!freehandle) freehandle = timedhandle;
-#endif
+  if (!freehandle && is_temp) {
+    freehandle = timedhandle_same_task ? timedhandle_same_task : timedhandle_any_task;
+    if (freehandle) {
+      NW_DIR *d = &(dirs[freehandle-1]);
+      XDPRINTF((3,0,"Recycle stale temp dhandle:%d old='%d:%s' oldtask=%d newtask=%d",
+              freehandle, d->volume, d->path ? (char*)d->path : "",
+              d->task, task));
+      if (d->path) {
+        xfree(d->path);
+        d->path = NULL;
+      }
+      d->inode = 0;
+    }
+  }
   if (freehandle){
     (void)change_dir_entry(&(dirs[freehandle-1]),
           volume, path, dev, inode,