Close tmpfile after writing

[lbonanomi]

This PR closes #624

Windows will not allow for deletion of a file that has an open handle.

Close tmpfile after writing to prevent unencrypted tmpfiles out-living
the execution of sops.

[codecov-commenter]

Codecov Report

Merging #685 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #685   +/-   ##
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  Coverage    38.23%   38.23%           
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  Files           23       23           
  Lines         3329     3329           
========================================
  Hits          1273     1273           
  Misses        1927     1927           
  Partials       129      129           

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[autrilla]

Does it actually fix the issue completely? We should probably delete the temp file entirely.

[lbonanomi]

Does it actually fix the issue completely?

I think so, but I didn't find the original problem and would like to get a confirmation from yourself (as a maintainer) and @xtrasolver (who opened the issue) before I say "done" with certainty.

We should probably delete the temp file entirely.

Yes indeed! Here's my 3-cent analysis: Linux lets you delete a file from disk while its open in an editor but Windows protects a file while it is open in an editor. Adding a close statement lets the downstream os.RemoveAll here to run to completion in git bash.

[autrilla]

Thanks for your explanation, I missed that we were actually deleting the entire directory.

However, you're currently closing the file before we're done using it. I'd add a defer before closing so the file is closed after the function has fully run. LGTM otherwise.

[lbonanomi]

Thanks for your explanation, I missed that we were actually deleting the entire directory.

However, you're currently closing the file before we're done using it. I'd add a defer before closing so the file is closed after the function has fully run. LGTM otherwise.

Per your instruction I added a defer. Just to be complete: this didn't influence my test results in git-bash. Thank you!

[autrilla]

Thanks!