Intialise dep_fd earlier to write negative dependencies correctly

[lions-tech]

During the execution of find_dofile we need to write to the dependency file; at least if a dofile is not found in the current directory. This is what redo_ifcreate called by check_dofile does.

However, the dependency file descriptor dep_fd is initiated after find_dofile is called.

As a result, the dep_fd for the first target is -1, so there are no negative dependencies to dofiles. Moreover, the negative dependencies are written to the dep_fd of the previous target. This behaviour is especially problematic, when writing the negative dependencies for the first target of a new subdirectory.

If you wish to reproduce this behaviour, you may use my dummy project: https://github.com/lions-tech/redo-c-testproj

[leahneukirchen]

Yes, but I think this needs more cleanup code now.

[lions-tech]

This might be due to my limited C knowledge, but I don't see anything that needs to be cleaned up.

I tested the implementation on my dummy project and it seemed to work fine. The temporary files were all renamed/removed correctly.

The find_dofile function doesn't seem to do anything else than writing to the dep_fd and creating the lock file and the target file after the dependency should'nt be a problem as well.

[leahneukirchen]

There are two exits and one return now that can leave around the tempfile.

[lions-tech]

I see what you mean. How about a generic tempfile cleanup function? I noticed tempfiles are also left over, if errors occured in the dofile.