It might happen - either by dragging the split view, or by other magical things - that the commit description pane is hidden, and cannot be shown again ever.
One possible repro:
- Resize the commit description splitter as low as possible
- Pull up the command history
=> See attachment for video of bug. Seems like the splitview ignores the minimum height when pulling up the command history.
A workaround is to execute the following in terminal defaults delete com.torusknot.SourceTreeNotMAS "NSSplitView Subview Frames repowindow_LogViewDescSplitter"