From 8a28b64b0c9df503ea09911bdc12b0531cf72533 Mon Sep 17 00:00:00 2001
From: xushiwei <x@goplus.org>
Date: Sun, 7 Jan 2024 21:48:03 +0800
Subject: [PATCH 1/2] Module.IsValid => HasModfile

---
 gopmod/module.go  |  5 -----
 modload/module.go | 20 +++++++++++++-------
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/gopmod/module.go b/gopmod/module.go
index ecbf4b9..cfec257 100644
--- a/gopmod/module.go
+++ b/gopmod/module.go
@@ -45,11 +45,6 @@ type Module struct {
 	depmods  []depmodInfo
 }
 
-// IsValid returns if this module exists or not.
-func (p *Module) IsValid() bool {
-	return p != nil && p.File != nil
-}
-
 // PkgType specifies a package type.
 type PkgType int
 
diff --git a/modload/module.go b/modload/module.go
index 24dc4ef..d204b11 100644
--- a/modload/module.go
+++ b/modload/module.go
@@ -41,18 +41,25 @@ type Module struct {
 	Opt *modfile.File
 }
 
-func (p Module) IsDefault() bool {
-	return p.Syntax == nil
+// HasModfile returns if this module exists or not.
+func (p Module) HasModfile() bool {
+	return p.Syntax != nil
 }
 
 // Modfile returns absolute path of the module file.
 func (p Module) Modfile() string {
-	return p.Syntax.Name
+	if syn := p.Syntax; syn != nil {
+		return syn.Name
+	}
+	return ""
 }
 
 // Root returns absolute root path of this module.
 func (p Module) Root() string {
-	return filepath.Dir(p.Syntax.Name)
+	if syn := p.Syntax; syn != nil {
+		return filepath.Dir(syn.Name)
+	}
+	return ""
 }
 
 // Path returns the module path.
@@ -207,11 +214,10 @@ func hasGopExtended(opt *modfile.File) bool {
 
 // Save saves all changes of this module.
 func (p Module) Save() (err error) {
-	if p.IsDefault() {
+	modfile := p.Modfile()
+	if modfile == "" {
 		return ErrSaveDefault
 	}
-
-	modfile := p.Modfile()
 	data, err := p.Format()
 	if err != nil {
 		return

From 5ae616baf0da4bc6afab70caa5df941012934f1d Mon Sep 17 00:00:00 2001
From: xushiwei <x@goplus.org>
Date: Sun, 7 Jan 2024 21:57:08 +0800
Subject: [PATCH 2/2] Module.PkgType fix: support Default module

---
 gopmod/module.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gopmod/module.go b/gopmod/module.go
index cfec257..9faf8a2 100644
--- a/gopmod/module.go
+++ b/gopmod/module.go
@@ -78,7 +78,7 @@ func (p *Module) PkgType(pkgPath string) PkgType {
 }
 
 func isPkgInMod(pkgPath, modPath string) bool {
-	if strings.HasPrefix(pkgPath, modPath) {
+	if modPath != "" && strings.HasPrefix(pkgPath, modPath) {
 		suffix := pkgPath[len(modPath):]
 		return suffix == "" || suffix[0] == '/'
 	}