Thank you for the clarification. Quoting the author:
“[Subtrees] are also not to be confused with using the subtree merge strategy. The main difference is that, besides merging the other project as a subdirectory, you can also extract the entire history of a subdirectory from your project and make it into a standalone project. Unlike the subtree merge strategy you can alternate back and forth between these two operations. If the standalone library gets updated, you can automatically merge the changes into your project; if you update the library inside your project, you can ‘split’ the changes back out again and merge them back into the library project.”
I guess I will have to get used to the idea that linking external repositories is harder than Subversion externals :) Which have serious limitations, I know, but at least they are so simple.
“[Subtrees] are also not to be confused with using the subtree merge strategy. The main difference is that, besides merging the other project as a subdirectory, you can also extract the entire history of a subdirectory from your project and make it into a standalone project. Unlike the subtree merge strategy you can alternate back and forth between these two operations. If the standalone library gets updated, you can automatically merge the changes into your project; if you update the library inside your project, you can ‘split’ the changes back out again and merge them back into the library project.”
https://github.com/apenwarr/git-subtree/blob/master/git-subt...
I guess I will have to get used to the idea that linking external repositories is harder than Subversion externals :) Which have serious limitations, I know, but at least they are so simple.