Add a regression test for recent regression in pair. (#97355)

PR #96165 broke code similar to this test, and was subsequently
reverted. Add a test-case, to ensure the problem won't reoccur.

This

Add a regression test for recent regression in pair. (#97355)

PR #96165 broke code similar to this test, and was subsequently
reverted. Add a test-case, to ensure the problem won't reoccur.

This error is potentially related to issues #59292 and #59966.

show more ...