Fixes for 'changes' and trailing newlines, for #291

[joshrabinowitz]

@sobolevn @BrandonCsSanders I think issue #291 & PR #292 might not be relevant for git-secret master.

I cannot reproduce #291 in my tests with git-secret master, (see the test "run 'changes' with no file changed" in tests/test_changes.bats )

Also I did some experimenting with #292 and master and I'm not sure it improves things.
(See new comments in src/commands/git_secret_changes.sh]

Am I missing something? Is there an issue with git-secret changes in master?

Edit: This fixes bugs in 'git secret changes' related to trailing newlines in file contents.
For details see the comments in #291

[joshrabinowitz]

@sobolevn look at this output in (for example) https://travis-ci.org/sobolevn/git-secret/jobs/473335843

"# 'run 'changes' on two files with no file changed' output: changes in /tmp/space file:", 
"# 'run 'changes' on two files with no file changed' output: ", 
"# 'run 'changes' on two files with no file changed' output: changes in /tmp/space file two:", 
"# 'run 'changes' on two files with no file changed': num lines is 3", 
"ok 16 run 'changes' on two files with no file changed", 

Should there be only 2 lines output instead of 3?

[sobolevn]

@joshrabinowitz yes, looks like so.

[joshrabinowitz]

I figured out the issue (but not the solution) to #291.

The underlying issue is that the $() construct used in
decrypted=$(_decrypt "$path" "0" "0" "$homedir" "$passphrase") (and elsewhere)
removes trailing newlines.

[joshrabinowitz]

@sobolevn This PR makes git secret changes work correctly with trailing newlines (#291), I think it's close to ready for merging.
Any comments?
Also, can you let me perform the squash-and-merge once you approve so I can edit the commit message (without cutting a new branch or performing a force push).

[sobolevn]

Looks good, but there is still some debug code inside.
👍

p.s. Happy New Year 🌲

[joshrabinowitz]

Thanks for the quick review @sobolevn ! And Happy New Year to you as well.