Lock folder, directly unlock fails with "Intermediate meta-data file missing"

[tobiasKaminsky]

Steps to reproduce:

• lock folder, store token
• unlock folder with token --> fails with above error

Reason I found it is (on Android):

• upload 1.png in encrypted folder -> works
• upload 1.png again
  • Android locks folder
  • checks for name collision
  • bails out
  • unlocks folder --> fails While upload never actually tried to modify something on server, we immediately locked (which I changed now), but still this should be possible.

My assumption is that this "sanity" check misses this case and it should only fail if there was an upload of payload.

@CarlSchwan as discussed