svn:externals problems during merge

Question

let's consider following SVN stucture:
* /Project_1/trunk/1.txt
* /Project_2/trunk/dir1
* /Project_2/trunk/dir2

Let's assume following scenario which leeds to an error:
* You add svn:externals to /Project_2/trunk/dir1 and /Project_2/trunk/dir2 so it looks like this:
svn:externals ^/Project_1/trunk/1.txt 1.txt
* Branch Project_2/trunk to a new branch and make some changes there
* Merge changes from trunk to your branch
* Commit merged changes to branch <-- if failes!

The error message is something like this: Error: Cannot commit both '.....\1.txt' and
Error: '.....\1.txt' as they refer to the same URL

Answer 1

The real answer is: Never, ever do svn:externals to versioned folder and/or single file. Bind only to folders and place them insinde new, unversioned folders