Due to limited resources, SSU has several known issues that will require time before they will be resolved. For some of them, a solution is already known. Before starting to hack at random, here are some documented notes:
Allowing the "multiple checkout" option to co-exist with SSU is a priority, but unfortunately there are no ways to trap the merge behaviour of "checkin" and bypass the visual merge tool. Maybe it's possible by using the DLL API, or some flags. Once some way is found to disable the automatic merge prompt, a simple 3-way merge can be done directly on the client by using base/head revision numbers.
Revision numbers should be transferred when files are checked-out or updated, along with file properties (line endings, etc). Apparently a separate "properties" invocation is required, possibly breaking the atomicity of the call and halving the get/checkout/update performance (which is already horrible). File properties are needed to:
SSU protocol allows the server to compare files by checksums directly. Currently ssserv maps SourceSafe paths to filenames using the "physical" command, and then compares file mtimes while maintaining a local hash cache to reduces the amount of time taken by "ss.exe".
More commands (besides "get" and "diff") could use/update this cache. Also, consider a passive and parallel thread to update this cache.
Directory listings (used very often for get commands) could be cached with the same method, provided that the whole hierarchy is checked.
Fixed by improving "dir" to scan the configured mappings first, make a list of required databases, list those, and post-process the result according to the mappings again. This is currently not done due to performance reasons.
On login, all databases should be probed before continuing. This is currently not done due to performance reasons.
File and directory names in ss.exe's output are truncated if excessively long, making it impossible to parse them correctly directly in "ssserv".
Parse README and put help strings directly in a module, to provide a more user-friendly interface.