fix: return correct package name for parsed package (#679)

Co-authored-by: Marc Vertes <mvertes@free.fr>

interp/interp.go

@@ -136,6 +136,7 @@ type Interpreter struct {
 	universe *scope            // interpreter global level scope
 	scopes   map[string]*scope // package level scopes, indexed by package name
 	srcPkg   imports           // source packages used in interpreter, indexed by path
+	pkgNames map[string]string // package names, indexed by path
 	done     chan struct{}     // for cancellation of channel operations
 }
 
@@ -213,6 +214,7 @@ func New(options Options) *Interpreter {
 		scopes:   map[string]*scope{},
 		binPkg:   Exports{"": map[string]reflect.Value{"_error": reflect.ValueOf((*_error)(nil))}},
 		srcPkg:   imports{},
+		pkgNames: map[string]string{},
 		rdir:     map[string]bool{},
 	}
 

interp/src.go

@@ -13,7 +13,7 @@ func (interp *Interpreter) importSrc(rPath, path string) (string, error) {
 	var err error
 
 	if interp.srcPkg[path] != nil {
-		return "", nil
+		return interp.pkgNames[path], nil
 	}
 
 	// For relative import paths in the form "./xxx" or "../xxx", the initial
@@ -111,6 +111,7 @@ func (interp *Interpreter) importSrc(rPath, path string) (string, error) {
 	// the global symbols in the package scope.
 	interp.mutex.Lock()
 	interp.srcPkg[path] = interp.scopes[path].sym
+	interp.pkgNames[path] = pkgName
 
 	interp.frame.mutex.Lock()
 	interp.resizeFrame()