Fix issue #595 - fileformat changed by gofmt

[cochran-at-niche]

A simple fix for issue #595.

When :GoFmt is called from within Vim, it runs the gofmt command with the -w parameter, which modifies the source file (actually, it modifies a temp file, which is then swapped in, but you get the idea). One effect of this is that all line endings are changed to lf. When the current buffer is reloaded, vim detects the fileformat as 'unix' due to the lf line endings, even if the fileformat was previously 'dos'. This makes it impossible to maintain windows-style line endings (crlf), if you want them.

Prior to this recent commit: 01578fd, this did not occur. I believe it has to do with the fact that the lines output from gofmt were previously split and inserted line-by-line via Vim itself, which respected the existing fileformat variable. However, in the this commit, the behavior was changed so that gofmt takes care of modifying the file externally, outside of vim (via the -w flag). As a result, the fileformat variable is no longer respected, and is actually changed upon reloading the buffer.

I'm not sure if you'll want to merge this pull-request, or simply accept unix-style line endings as the only valid line-endings for a Go file (this seems to be the convention adopted by the authors of Go: golang/go#3961). In any case, I thought I'd bring it to your attention, because I, at least, wanted to keep using windows-style line endings on my windows machine (I let git do the conversion for me), and I expect that other people might want the same.

Thanks!

[fatih]

Hi @cochran-at-niche

This totally makes sense. I'm ok to merge it as I really don't want to change anythign. Just the order of saving and restoring the filetype seems to be wrong. Shouldn't we save before the renaming? silent edit! just reloads the file actually. Again not sure, can you test it?

[cochran-at-niche]

I'm 99% sure that the fileformat variable is changed when the file/buffer is reloaded (silent edit!) - that's when vim attempts to detect the fileformat, and ends up setting it to 'unix'. I can confirm that it fixed the issue for me, at least.

In any case, I went ahead and changed it so that the fileformat is saved before the temp file is renamed, just to be safe.

[fatih]

Thanks @cochran-at-niche

[cochran-at-niche]

You're welcome! :)