[PATCH 1/1] t7406: avoid failures solely due to timing issues

From: Johannes Schindelin <johannes.schindelin@gmx.de>

Regression tests are automated tests which try to ensure a specific behavior. The idea is: if the test case fails, the behavior indicated in the test case's title regressed.

If a regression test that fails, even occasionally, for any reason other than to indicate the particular regression(s) it tries to catch, it is less useful than when it really only fails when there is a bug in the (non-test) code that needs to be fixed.

In the instance of the test case "submodule update --init --recursive from subdirectory" of the script t7406-submodule-update.sh, the exact output of a recursive clone is compared with a pre-generated one. And this is a racy test because the structure of the submodules only guarantees a *partial* order. The 'none' and the 'rebasing' submodules *can* be cloned in any order, which means that a mismatch with the hard-coded order does not necessarily indicate a bug in the tested code.

See for example: https://git-for-windows.visualstudio.com/git/_build/results?buildId=14035&view=logs

To prevent such false positives from unnecessarily costing time when investigating test failures, let's take the exact order of the lines out of the equation by sorting them before comparing them.

This test script seems not to have any more test cases that try to verify any specific order in which recursive clones process the submodules, therefore this is the only test case that is changed in this manner.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 t/t7406-submodule-update.sh | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)