Thanks for adding --no-single-branch in case of depth != 0.

One idea we had and which also would help us when different configurations build different git branches:

A checkbox with "Clone only specified branch" in the additional options of the git repository.

This would be applied without taking the depth parameter into account. The only thing to consider here is that if depth != 0 the "--no-single-branch" option is now added, but must not be added if --branch=xy is specified in the command line.

so if the checkbox is not checked the command would look similar to
when depth != 0: git clone --depth=50 --no-single-branch <url>
when depth == 0: git clone <url>

if the checkbox is checked:
when depth != 0: git clone --depth=50 --branch=my-release-branch <url>
when depth == 0: git clone --branch=my-release-branch <url>

and the concern was that it would be confusing when a second branch option is introduced. But I think a checkbox with a meaningful description would not be a problem.

If you have any question, please do not hesitate to ask.

And just as a little side note why this would help us a lot: These
full clone without depth 719 MB

depth all branches master-only release-branch-only
00001 157 MB 71 MB 57 MB
00010 192 MB 74 MB 57 MB
00100 283 MB 265 MB 117 MB
01000 295 MB 278 MB 122 MB
10000 362 MB 345 MB 162 MB

So a single branch clone with specified branch would help us a lot as we have tons of configurations