Manager: allow backslashes in variables

Windows machines should be able to simply use backslashes.

internal/manager/config/config.go

@@ -378,15 +378,7 @@ func (c *Conf) constructVariableLookupTableForVars(vars map[string]Variable) {
 			// Given a variable 'apps' with value '/path/to/apps',
 			// '/path/to/apps/blender' should be remapped to '{apps}/blender'.
 			if variable.IsTwoWay {
-				if strings.Contains(value.Value, "\\") {
-					log.Warn().
-						Str("variable", name).
-						Str("audience", string(value.Audience)).
-						Str("platform", string(value.Platform)).
-						Str("value", value.Value).
-						Msg("Backslash found in variable value. Change paths to use forward slashes instead.")
-				}
-				value.Value = strings.TrimRight(value.Value, "/")
+				value.Value = crosspath.TrimTrailingSep(value.Value)
 			}
 
 			if value.Platform != "" {

pkg/crosspath/crosspath.go

@@ -149,3 +149,16 @@ func pathSepForPlatform(platform string) string {
 func isPathSep(r rune) bool {
 	return r == '/' || r == '\\'
 }
+
+// TrimTrailingSep removes any trailling path separator.
+func TrimTrailingSep(path string) string {
+	if path == "" {
+		return ""
+	}
+
+	trimmed := strings.TrimRightFunc(path, isPathSep)
+	if trimmed == "" {
+		return string([]rune(path)[0])
+	}
+	return trimmed
+}

pkg/crosspath/crosspath_test.go

@@ -1,7 +1,5 @@
 package crosspath
 
-// SPDX-License-Identifier: GPL-3.0-or-later
-
 import (
 	"path"
 	"path/filepath"
@@ -237,3 +235,35 @@ func TestToPlatform(t *testing.T) {
 		})
 	}
 }
+
+func TestTrimTrailingSep(t *testing.T) {
+	type args struct {
+		path string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{"empty", args{""}, ""},
+		{"single-slash", args{`/`}, `/`},
+		{"single-backslash", args{`\`}, `\`},
+		{"multiple-slashes", args{`///`}, `/`},
+		{"multiple-backslashes", args{`\\\`}, `\`},
+		{"multiple-mixed-slash-first", args{`/\\`}, `/`},
+		{"multiple-mixed-backslash-first", args{`\//`}, `\`},
+		{"nothing-trailing", args{`nothing/trailing\here`}, `nothing/trailing\here`},
+		{"trailing-space", args{`trailing/space/ `}, `trailing/space/ `},
+		{"trailing-slash", args{`trailing/slash/`}, `trailing/slash`},
+		{"trailing-slashes", args{`trailing/slashes///`}, `trailing/slashes`},
+		{"trailing-backslash", args{`trailing\backslash\`}, `trailing\backslash`},
+		{"trailing-backslashes", args{`trailing\backslashes\\\`}, `trailing\backslashes`},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := TrimTrailingSep(tt.args.path); got != tt.want {
+				t.Errorf("TrimTrailingSep() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}