Make tree conflict detection notice modifications deep inside a tree that
"update" is about to delete.

### FAIL: depth_tests.py 25

* subversion/libsvn_wc/update_editor.c
  (modcheck_baton_t): New data type.
  (modcheck_found_entry, modcheck_handle_error, tree_has_local_mods): New
    functions.
  (check_tree_conflict): Use tree_has_local_mods() to detect deep mods.

* subversion/tests/cmdline/update_tests.py
  (update_delete_modified_files): Expect another conflict.

Index: subversion/tests/cmdline/update_tests.py
===================================================================
--- subversion/tests/cmdline/update_tests.py	(revision 33519)
+++ subversion/tests/cmdline/update_tests.py	(working copy)
@@ -656,6 +656,7 @@
   expected_output = svntest.wc.State(wc_dir, {
     'A/B/E'       : Item(status='C '), # tree conflict (issue #2282)
     'A/B/E/alpha' : Item(status='D '),
+    'A/D'         : Item(status='C '), # tree conflict (issue #2282)
     'A/D/G'       : Item(status='D '),
     })
   expected_disk = svntest.main.greek_state.copy()
@@ -670,6 +671,7 @@
   expected_status = svntest.actions.get_virginal_state(wc_dir, 2)
   expected_status.tweak('A/B/E', status='C ') # tree conflict (issue #2282)
   expected_status.remove('A/B/E/alpha')
+  expected_status.tweak('A/D', status='C ') # tree conflict (issue #2282)
   expected_status.remove('A/D/G')
   expected_status.remove('A/D/G/pi')
   expected_status.remove('A/D/G/rho')
Index: subversion/libsvn_wc/update_editor.c
===================================================================
--- subversion/libsvn_wc/update_editor.c	(revision 33577)
+++ subversion/libsvn_wc/update_editor.c	(working copy)
@@ -1071,6 +1071,10 @@
   return err;
 }
 
+
+/* ===================================================================== */
+/* Checking for local modifications. */
+
 /* Set *MODIFIED to true iff the item described by (ADM_ACCESS, FULL_PATH,
  * KIND) has local modifications.
  * For a file, this means text mods or property mods.
@@ -1101,6 +1105,74 @@
   return SVN_NO_ERROR;
 }
 
+/* A baton for use with modcheck_found_entry(). */
+typedef struct modcheck_baton_t {
+  svn_wc_adm_access_t *adm_access;  /* access for the root of the sub-tree */
+  svn_boolean_t found_mod;  /* whether a modification has been found */
+} modcheck_baton_t;
+
+static svn_error_t *
+modcheck_found_entry(const char *path,
+                     const svn_wc_entry_t *entry,
+                     void *walk_baton,
+                     apr_pool_t *pool)
+{
+  modcheck_baton_t *baton = walk_baton;
+  svn_wc_adm_access_t *adm_access;
+  svn_boolean_t modified;
+
+  SVN_ERR(svn_wc_adm_probe_retrieve(&adm_access, baton->adm_access, path,
+                                    pool));
+  SVN_ERR(entry_has_local_mods(&modified, adm_access, entry->kind, path, pool));
+  if (modified)
+    baton->found_mod = TRUE;
+
+  return SVN_NO_ERROR;
+}
+
+static svn_error_t *
+modcheck_handle_error(const char *path,
+                      svn_error_t *err,
+                      void *walk_baton,
+                      apr_pool_t *pool)
+{
+  return err;
+}
+
+/* Set *MODIFIED to true iff there are any local modifications within the
+ * tree rooted at PATH whose admin access baton is ADM_ACCESS. PATH may be a
+ * file or a directory. */
+static svn_error_t *
+tree_has_local_mods(svn_boolean_t *modified,
+                    const char *path,
+                    svn_wc_adm_access_t *adm_access,
+                    apr_pool_t *pool)
+{
+
+  static svn_wc_entry_callbacks2_t modcheck_callbacks =
+    { modcheck_found_entry, modcheck_handle_error };
+  modcheck_baton_t modcheck_baton = { NULL, FALSE };
+
+  modcheck_baton.adm_access = adm_access;
+
+  /* Walk the WC tree to its full depth, looking for any local modifications.
+   * If it's a "sparse" directory, that's OK: there can be no local mods in
+   * the pieces that aren't present in the WC. */
+
+  /* ### TODO: If this tree is not (read-) locked to depth infinity, e.g.
+   * because of "svn update --depth=immediates", this will error out. We first
+   * need to extend the lock deeper. */
+
+  SVN_ERR(svn_wc_walk_entries3(path, adm_access,
+                               &modcheck_callbacks, &modcheck_baton,
+                               svn_depth_infinity, FALSE /* show_hidden */,
+                               NULL /* cancel_func */, NULL /* cancel_baton */,
+                               pool));
+
+  *modified = modcheck_baton.found_mod;
+  return SVN_NO_ERROR;
+}
+
 /* Check whether the incoming change ACTION on FULL_PATH would conflict with
  * FULL_PATH's scheduled change. If so, then raise a tree conflict with
  * FULL_PATH as the victim, by appending log actions to LOG_ACCUM.
@@ -1183,21 +1255,13 @@
                */
               SVN_ERR(svn_wc_adm_probe_retrieve(&adm_access, parent_adm_access,
                                                 full_path, pool));
-              SVN_ERR(entry_has_local_mods(&modified, adm_access,
-                                           entry->kind, full_path, pool));
-
-
-              /* ### TODO: Also detect deep modifications in a directory tree.
-               *   The update editor will not visit subdirectories of a
-               *   directory it wants to delete. Therefore, we need to start
-               *   a separate crawl here to make sure the directory tree we
-               *   are about to delete hasn't been locally modified anywhere.
-               */
-#if 0
-              SVN_ERR(subtrees_have_local_mods(&modified, parent_adm_access,
-                                                entry, full_path, pool));
-#endif
 
+              /* Detect deep modifications in a directory tree.
+               * The update editor will not visit subdirectories of a
+               * directory it wants to delete. Therefore, we need to start
+               * a separate crawl here. */
+              SVN_ERR(tree_has_local_mods(&modified, full_path, adm_access,
+                                          pool));
               if (modified)
                 {
                   reason = svn_wc_conflict_reason_edited;