Add zipinsecurepath to rwp (#103)

cmd/rwp/main.go

@@ -1,7 +1,22 @@
 package main
 
-import "github.com/readium/go-toolkit/cmd/rwp/cmd"
+import (
+	"os"
+
+	"github.com/readium/go-toolkit/cmd/rwp/cmd"
+)
 
 func main() {
+	// From the archive/zip docs:
+	// If any file inside the archive uses a non-local name
+	// (as defined by [filepath.IsLocal]) or a name containing backslashes
+	// and the GODEBUG environment variable contains `zipinsecurepath=0`,
+	// NewReader returns the reader with an [ErrInsecurePath] error.
+	if os.Getenv("GODEBUG") == "" {
+		os.Setenv("GODEBUG", "zipinsecurepath=0")
+	} else {
+		os.Setenv("GODEBUG", os.Getenv("GODEBUG")+",zipinsecurepath=0")
+	}
+
 	cmd.Execute()
 }