Fix 'arc patch' when adding files in new directories

Summary:
If you apply an arcbundle to a subversion working copy which adds
files in new subdirectories, we fail to create and add the parent directories
so the whole operation fails. Make sure we create and add any missing parent
directories before apply patches.

Test Plan:
Applied Facebook diff #542056 to www@rE349795 cleanly, while it
failed previously.

Reviewed By: aran
Reviewers: aran
CC: aran
Differential Revision: 62

src/workflow/patch/ArcanistPatchWorkflow.php

@@ -237,6 +237,21 @@ EOTEXT
         }
       }
 
+      // Before we start doing anything, create all the directories we're going
+      // to add files to if they don't already exist.
+      foreach ($copies as $copy) {
+        list($src, $dst) = $copy;
+        $this->createParentDirectoryOf($dst);
+      }
+
+      foreach ($patches as $path => $patch) {
+        $this->createParentDirectoryOf($path);
+      }
+
+      foreach ($adds as $add) {
+        $this->createParentDirectoryOf($add);
+      }
+
       foreach ($copies as $copy) {
         list($src, $dst) = $copy;
         passthru(
@@ -336,4 +351,28 @@ EOTEXT
     // TODO: Pull open diffs from 'arc list'?
     return array('ARGUMENT');
   }
+
+  /**
+   * Create parent directories one at a time, since we need to "svn add" each
+   * one. (Technically we could "svn add" just the topmost new directory.)
+   */
+  private function createParentDirectoryOf($path) {
+    $repository_api = $this->getRepositoryAPI();
+    $dir = dirname($path);
+    if (Filesystem::pathExists($dir)) {
+      return;
+    } else {
+      // Make sure the parent directory exists before we make this one.
+      $this->createParentDirectoryOf($dir);
+      execx(
+        '(cd %s && mkdir %s)',
+        $repository_api->getPath(),
+        $dir);
+      passthru(
+        csprintf(
+          '(cd %s && svn add %s)',
+          $repository_api->getPath(),
+          $dir));
+    }
+  }
 }