Update filename on werkzeug FileStorage for uploaded files

This is an issue for fields whose name might be changed at any point, like any image ending in "jpeg" (which will be renamed to "jpg". That would cause the actual file to be saved to disk with ".jpeg", but be saved elsewhere as ".jpg".

This example (mostly copied from the example in `examples/forms/simple.py`) shows it better than I can explain:

    import os
    from flask import Flask
    from flask.ext.admin import Admin, form
    from flask.ext.admin.contrib import sqla
    from flask.ext.sqlalchemy import SQLAlchemy

    app = Flask(__name__)
    app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///hello.db'
    db = SQLAlchemy(app)

    os.path.isdir('static') or os.mkdir('static')

    class Photo(db.Model):
        id = db.Column(db.Integer, primary_key=True)
        path = db.Column(db.Unicode(128))

    class PhotoView(sqla.ModelView):
        form_extra_fields = {'path': form.ImageUploadField('Photo', base_path='static')}

    admin = Admin(app, 'Photos are broken!')
    admin.add_view(PhotoView(Photo, db.session))

    db.create_all()
    app.run(debug=True)

... try uploading files with `.jpeg` vs `.jpg` extensions. It's pretty broken.

flask_admin/form/upload.py

@@ -208,6 +208,8 @@ class FileUploadField(fields.TextField):
 
             filename = self.generate_name(obj, self.data)
             filename = self._save_file(self.data, filename)
+            # update filename of FileStorage to our validated name
+            self.data.filename = filename
 
             setattr(obj, name, filename)
 

flask_admin/tests/test_form_upload.py

@@ -95,6 +95,10 @@ def test_image_upload_field():
         safe_delete(path, 'test2.png')
         safe_delete(path, 'test2_thumb.jpg')
         safe_delete(path, 'test1.jpg')
+        safe_delete(path, 'test1.jpeg')
+        safe_delete(path, 'test1.gif')
+        safe_delete(path, 'test1.png')
+        safe_delete(path, 'test1.tiff')
 
     class TestForm(form.BaseForm):
         upload = form.ImageUploadField('Upload',
@@ -204,6 +208,19 @@ def test_image_upload_field():
             ok_(op.exists(op.join(path, 'test1.jpg')))
 
 
+    # check allowed extensions
+    for extension in ('gif', 'jpg', 'jpeg', 'png', 'tiff'):
+        filename = 'copyleft.' + extension
+        filepath = op.join(op.dirname(__file__), 'data', filename)
+        with open(filepath, 'rb') as fp:
+            with app.test_request_context(method='POST', data={'upload': (fp, filename)}):
+                my_form = TestNoResizeForm(helpers.get_form_data())
+                ok_(my_form.validate())
+                my_form.populate_obj(dummy)
+                eq_(dummy.upload, my_form.upload.data.filename)
+
+
+
 def test_relative_path():
     app = Flask(__name__)