internal/util/projutil/project_util.go: fix repo lookup when CWD is $GOPATH/src

[joelanford]

Description of the change:
Fixes logic that extracts repo portion of path from $GOPATH when CWD is $GOPATH/src

Motivation for the change:
Closes #1423

[estroz]

Does this fix the issue? strings.TrimPrefix(currPkg, fsep) should remove fsep from currPkg regardless of whether it is replaced above.

[joelanford]

Does this fix the issue? strings.TrimPrefix(currPkg, fsep) should remove fsep from currPkg regardless of whether it is replaced above.

It does. Here's a line-by-line explanation:

Old way:

gopath := MustSetGopath(MustGetGopath())          // gopath = "/home/user/go"
goSrc := filepath.Join(gopath, SrcDir)            // goSrc = "/home/user/go/src"
wd := MustGetwd()                                 // wd = "/home/user/go/src"
currPkg := strings.Replace(wd, goSrc+fsep, "", 1) // currPkg = "/home/user/go/src"
// strip any "/" prefix from the repo path.
return strings.TrimPrefix(currPkg, fsep)          // return "home/user/go/src"

New way:

gopath := MustSetGopath(MustGetGopath())     // gopath = "/home/user/go"
goSrc := filepath.Join(gopath, SrcDir)       // goSrc = "/home/user/go/src"
wd := MustGetwd()                            // wd = "/home/user/go/src"
currPkg := strings.Replace(wd, goSrc, "", 1) // currPkg = ""
// strip any "/" prefix from the repo path.
return strings.TrimPrefix(currPkg, fsep)     // return ""

In the old way, the extra fsep in strings.Replace causes the prefix not to be matched when wd and goSrc are equal, resulting in no replacement.

[estroz]

Ah so if we're in the first child directory of $GOPATH/src this won't work, but does if we're in a grandchild directory. Nice catch.

[estroz]

/lgtm