Merge failure when main was branched before first load

[philrz]

If I branch a pool before my first commit to main, when I merge to main later it ultimately fails.

$ zed merge -use logs@staging main
no path for nil commit ID

Details

Repro is with Zed commit f530788.

If I branch after having loaded some data to main, my merge succeeds.

$ zed -version
Version: v1.11.1-9-gf530788f

$ zed init
lake created: file:///Users/phil/.local/share/zed

$ zed create -orderby ts:desc logs
pool created: logs 2Ylf83QfvyR4bLkwdQSs3fOI9BF

$ zed load -use logs@main capture_loss.log.gz 
(1/1) 270B/270B 270B/s 100.00%
2Ylf8WAyQTAGt653uOV3BpQYPih committed

$ zed branch -use logs@main staging
"staging": branch created

$ zed load -use logs@staging dpd.log.gz 
(1/1) 1211B/1211B 1211B/s 100.00%
2YlfBZmFzLqxaPAqe3o6Nfrz3nC committed

$ zed merge -use logs@staging main
"staging": merged into branch "main"

However, if I branch before my first commit to main, the merge ultimately fails.

$ zed init
lake created: file:///Users/phil/.local/share/zed

$ zed create -orderby ts:desc logs
pool created: logs 2YlfDhBPz0s862XVPGefQyPE1Iy

$ zed branch -use logs@main staging
"staging": branch created

$ zed load -use logs@staging capture_loss.log.gz 
(1/1) 270B/270B 270B/s 100.00%
2YlfEbhtFFtIJ0DbtdWzHyr8Qhj committed

$ zed load -use logs@staging dpd.log.gz 
(1/1) 1211B/1211B 1211B/s 100.00%
2YlfF807kGYXnP8eug3DUTXbrs0 committed

$ zed merge -use logs@staging main
no path for nil commit ID