#1639 Password protected archive can become impossible to uncompress

[apalou]

Hello,

I think I found a way to make a file within an archive impossible to extract.
(7-zip 15.14, Windows 7 Pro)
Steps to produce:
1) create an archive (e.g. test.7z)
2) Add a file (file1) with password protection (pass1), but unencrypted filenames
2) right click a second file (file2) -> Add to archive... -> test.7z with another password (pass2) AND encrypt filenames
The archive need "pass2" to open/list content; file1 can no more be extracted. With older version (I tried 9.20), removing file2 from the archive also removed the filename's encryption (i.e. pass2), but with 15.14 it is no more the case. The result is an archive with a password to decrypt filenames, but another password to
decrypt content... As it is not possible to provide both passwords, file1 is locked in the archive.

I post the file created as described above.

[apalou]

I tested, using steps above, with 7-zip 16.04; problem still there.
Why not simply let the user decide if the password should be cached or not (i.e. check-box on password request dialog)?