BeyondCompare: Wrong 3-way diff for automatic merges

Issue #2147 on hold
created an issue

Reproduced in TortoiseHg 2.4.3

Bare with me. This bug is easy to reproduce but the explanation is a bit long :)

  1. From TortoiseHg Workbench, select a revision to merge against.
  2. The target revision should contain a single file that has changed in a manner that can be merged automatically.
  3. "Merge with Local"
  4. "1 files were modified on both branches and must be resolved". Click on "resolved"
  5. Select the single file, and click on "Tool resolve". The file will get resolved without any interaction and move to the bottom window.
  6. Select the resolved file in the bottom window, then click on 3-way diff.
  7. BeyondCompare is launched with the following arguments: "bcompare /tmp/thg.Ic6pW8/empty /tmp/thg.Ic6pW8/.../newRevision/file.txt /tmp/thg.Ic6pW8/.../oldRevision/file.txt"
  8. The BeyondCompare window is split into three: empty, "file.txt[merged]", "file.txt@newReviison"

Expected behavior: left tab should contain one revision, the middle tab should contain the "base" revision, the right tab should contain the other revision.

This is reproducible always.