Remove assumption of ascii paths

On for example a linux system with a Japanese locale, the user-dirs.dirs
file can contain paths with japanese characters, breaking the
byte-offset-based path processing. To fix this, we switch to
chop/chopprefix instead, and while we're at it make a similar fix in the
setxdg macro implementation.

A test based on the Japanese user-dirs.dirs is created.

Reported-by: ujimushi at Slashdot Japan <10514830+ujimushi@users.noreply.github.com>

src/BaseDirs.jl

@@ -1,5 +1,26 @@
 module BaseDirs
 
+# Compat
+@static if VERSION < v"1.8"
+    function chopsuffix(s::Union{String, SubString{String}},
+                        suffix::Union{String, SubString{String}})
+        if !isempty(suffix) && endswith(s, suffix)
+            astart = ncodeunits(s) - ncodeunits(suffix) + 1
+            @inbounds SubString(s, firstindex(s), prevind(s, astart))
+        else
+            SubString(s)
+        end
+    end
+    function chopprefix(s::Union{String, SubString{String}},
+                        prefix::Union{String, SubString{String}})
+        if startswith(s, prefix)
+            SubString(s, 1 + ncodeunits(prefix))
+        else
+            SubString(s)
+        end
+    end
+end
+
 include("variables.jl")
 
 function reload end

src/internals.jl

@@ -10,20 +10,14 @@ export @defaccessor, @setxdg, @setxdgs
 @static if Sys.isunix()
     macro setxdg(envvar::Symbol, default)
         quote $(esc(envvar))[] = if haskey(ENV, $("XDG_$envvar")) && !isempty(ENV[$("XDG_$envvar")])
-            path = ENV[$("XDG_$envvar")]
-            if endswith(path, first(Base.Filesystem.path_separator))
-                path[begin:end-1]
-            else path end
+            chopsuffix(ENV[$("XDG_$envvar")], Base.Filesystem.path_separator)
         else expanduser($(esc(default))) end
         end
     end
 else
     macro setxdg(envvar::Symbol, default)
         quote $(esc(envvar))[] = if haskey(ENV, $("XDG_$envvar")) && !isempty(ENV[$("XDG_$envvar")])
-            path = ENV[$("XDG_$envvar")]
-            if endswith(path, first(Base.Filesystem.path_separator))
-                path[begin:end-1]
-            else path end
+            chopsuffix(ENV[$("XDG_$envvar")], Base.Filesystem.path_separator)
         else $(esc(default)) end
         end
     end
@@ -32,9 +26,7 @@ end
 macro setxdgs(envvar::Symbol, defaults)
     quote $(esc(envvar))[] = if haskey(ENV, $("XDG_$envvar")) && !isempty(ENV[$("XDG_$envvar")])
         map(split(ENV[$("XDG_$envvar")], ':')) do path
-            if endswith(path, first(Base.Filesystem.path_separator))
-                path[begin:end-1]
-            else path end
+            chopsuffix(path, Base.Filesystem.path_separator)
         end
     else $(esc(defaults)) end
     end

src/unix.jl

@@ -20,10 +20,10 @@ function parseuserdirs(configdir::String)
                 key, value = split(line, '=', limit=2)
                 if key in validnames
                     if startswith(value, '"') && endswith(value, '"')
-                        value = unescape_string(value[2:end-1])
+                        value = unescape_string(chop(value, head=1, tail=1))
                     end
                     if startswith(value, "\$HOME")
-                        value = string(homedir(), value[6:end])
+                        value = string(homedir(), chopprefix(value, "\$HOME"))
                     end
                     if startswith(value, '/')
                         push!(keys, Symbol(key))

test/runtests.jl

@@ -115,6 +115,34 @@ elseif Sys.isunix()
         @test BaseDirs.User.fonts() == ["$usr/.local/share/fonts", "$usr/.fonts"]
         @test BaseDirs.User.applications() == ["$usr/.local/share/applications"]
     end
+    @testset "User (customised)" begin
+        userdirs_jpn = raw"""
+        XDG_DESKTOP_DIR="$HOME/デスクトップ"
+        XDG_DOWNLOAD_DIR="$HOME/ダウンロード"
+        XDG_TEMPLATES_DIR="$HOME/テンプレート"
+        XDG_PUBLICSHARE_DIR="$HOME/公開"
+        XDG_DOCUMENTS_DIR="$HOME/ドキュメント"
+        XDG_MUSIC_DIR="$HOME/ミュージック"
+        XDG_PICTURES_DIR="$HOME/ピクチャ"
+        XDG_VIDEOS_DIR="$HOME/ビデオ"
+        """
+        userdirs_file = joinpath(BaseDirs.CONFIG_HOME[], "user-dirs.dirs")
+        isfile(userdirs_file) &&
+            mv(userdirs_file, userdirs_file * ".backup")
+        write(userdirs_file, userdirs_jpn)
+        @test BaseDirs.reload() === nothing
+        @test BaseDirs.User.desktop() == "$usr/デスクトップ"
+        @test BaseDirs.User.downloads() == "$usr/ダウンロード"
+        @test BaseDirs.User.documents() == "$usr/ドキュメント"
+        @test BaseDirs.User.music() == "$usr/ミュージック"
+        @test BaseDirs.User.pictures() == "$usr/ピクチャ"
+        @test BaseDirs.User.videos() == "$usr/ビデオ"
+        @test BaseDirs.User.templates() == "$usr/テンプレート"
+        @test BaseDirs.User.public() == "$usr/公開"
+        rm(userdirs_file)
+        isfile(userdirs_file * ".backup") &&
+            mv(userdirs_file * ".backup", userdirs_file)
+    end
     @testset "System" begin
         @test BaseDirs.System.data() == ["/usr/local/share", "/usr/share"]
         @test BaseDirs.System.config() == ["/etc/xdg"]