Magento 1.9 Image Fallback?

Question

I am working with the Sass fallback structure and couldn't find any documentation on whether image folder fallbacks are also supported. I have set up my dev site as follows with 2 custom packages and themes:

skin/frontend/custom_package1/custom_theme1 skin/frontend/custom_package2/custom_theme2

Here is the config.rb file for custom_package1/custom_theme1:

add_import_path "../../../rwd/default/scss"
http_path = "/skin/frontend/custom_package1/custom_theme1/"
css_dir = "../css"
sass_dir = "../scss"
images_dir = "../images"
javascripts_dir = "../js"
relative_assets = true
sourcemap = true

output_style = :expanded
environment = :development

Here is the config.rb file for custom_package2/custom_theme2:

add_import_path "../../../custom_package/custom_theme/scss"
http_path = "/skin/frontend/custom_package2/custom_theme2/"
css_dir = "../css"
sass_dir = "../scss"
images_dir = "../images"
javascripts_dir = "../js"
relative_assets = true
sourcemap = true

output_style = :expanded
environment = :development

The scss files are falling back correctly. If they are not found in custom_package2/custom_theme2.... it checks custom_package1/custom_theme1... if not there it checks rwd/default...

The images do not appear to be falling back. I have the following file structure:

custom_package2/custom_theme2/images/ contains...
logo.gif

custom_package1/custom_theme1/images/ contains...
icon_sprite.png

When trying to load icon_sprite.png on the page I get a 404 error because it's looking for the image at custom_package2/custom_theme2/images/icon_sprite.png, which doesn't exist.

Questions:

1. Is image fallback supposed to work the same as scss fallback?
2. If so, how should I correctly set this up?

So far I've tried adding another import path to each config.rb:

custom_package2/custom_theme2/config.rb:

add_import_path "../../../custom_package1/custom_theme1/images"

custom_package1/custom_theme1/config.rb:

add_import_path "../../../rwd/default/images"

Answer 1

It depends on how you reference the image.

If you reference the image in a template file via a call to $this->getSkinUrl('images/sth.jpg'), then the fallback should work as expected.

But if you reference the image in a SCSS file with e.g.

.sth {
    background: url("../images/sth.jpg");
}

Then there is no other chance than copying the respective image to the child theme. Unfortunately, there is no add_import_path for images. add_import_path can only be used for SASS files. And the image-url function does not check if the file exists. It simply returns a URL relative to the images path.