fix PNG.Check() logic

Author: J-Siu

CHANGELOG.md

@@ -34,3 +34,5 @@
 - v2.0.4
   - update go-helper/v2
   - update root.go
+- v2.0.5
+  - fix PNG.Check() logic

cmd/root.go

@@ -51,29 +51,24 @@ var rootCmd = &cobra.Command{
 		if len(args) < 2 {
 			errs.Queue("", errors.New("Input/Output file missing"))
 		}
-
-		// --- Pre-checking
-
-		var icoFile string
-		if errs.IsEmpty() {
-			// Make sure the last file in arg list is *NOT* PNG, to prevent accidental overwriting a PNG file
+	},
+	Run: func(cmd *cobra.Command, args []string) {
+		var (
+			ico     *p2i.ICO
 			icoFile = args[len(args)-1]
-			png := new(p2i.PNG).New().Read(icoFile)
+			png     *p2i.PNG
+			pngNum  = len(args) - 1
+		)
+		if errs.IsEmpty() {
+			// check if output file is PNG
+			png = new(p2i.PNG).New().Read(icoFile)
 			if png.Err == nil && png.IsPNG() {
 				errs.Queue("", errors.New(png.File+": is PNG"))
 			} else {
 				// Clear the errs queue, as the icoFile may not exist yet and generated a read error
 				errs.Clear()
 			}
 		}
-
-	},
-	Run: func(cmd *cobra.Command, args []string) {
-		var (
-			ico     *p2i.ICO
-			icoFile = args[len(args)-1]
-			pngNum  = len(args) - 1
-		)
 		if errs.IsEmpty() {
 			ico = new(p2i.ICO).New(icoFile)
 			for i := range pngNum {

go.mod

@@ -1,15 +1,15 @@
 module github.com/J-Siu/go-png2ico/v2
 
-go 1.25.1
+go 1.25.5
 
 require (
-	github.com/J-Siu/go-helper/v2 v2.6.5
+	github.com/J-Siu/go-helper/v2 v2.7.1
 	github.com/spf13/cobra v1.10.2
 )
 
 require (
 	github.com/charlievieth/strcase v0.0.5 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/spf13/pflag v1.0.10 // indirect
-	golang.org/x/sys v0.39.0 // indirect
+	golang.org/x/sys v0.40.0 // indirect
 )

go.sum

@@ -1,5 +1,5 @@
-github.com/J-Siu/go-helper/v2 v2.6.5 h1:EVTjsBacgeT0CUvsCXGSxWgZGLo+5kvJz771HiGG7MM=
-github.com/J-Siu/go-helper/v2 v2.6.5/go.mod h1:xMmpBESfx/Z5eab1bTNgu6YpEOvBZUorjNfLdGu4fN4=
+github.com/J-Siu/go-helper/v2 v2.7.1 h1:fq6e/5xfUGxh/Y2gbnzwWUGzZjl5x7YsdgcQmrx4nwc=
+github.com/J-Siu/go-helper/v2 v2.7.1/go.mod h1:8cC+sNocdV2FB7gJJ5pGiwG+tnlkoepFEsu4wyp6Its=
 github.com/charlievieth/strcase v0.0.5 h1:gV4iXVyD6eI5KdfOV+/vIVCKXZwtCWOmDMcu7Uy00Rs=
 github.com/charlievieth/strcase v0.0.5/go.mod h1:FIOYY1aDBMSIOFqmVomHBpoK+bteGlESRsgsdWjrhx8=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
@@ -12,6 +12,6 @@ github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An
 github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
 github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
-golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
-golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
+golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

p2i/png.go

@@ -80,18 +80,14 @@ func (t *PNG) Check() *PNG {
 
 	// CHECK 1: 8byte header[0:8] - magic number
 	magic := []byte{0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a}
-	if bytes.Equal(magic[:], t.Buf[:8]) {
+	t.isPNG = bytes.Equal(magic[:], t.Buf[:8])
+	if t.isPNG {
 		ezlog.Debug().N(prefix).M("Found PNG magic").Out()
-		t.isPNG = true
-	}
-
-	// CHECK 2: 4byte header[12:16] - chunk type IHDR
-	if t.isPNG && bytes.Equal([]byte("IHDR"), t.Buf[12:16]) {
-		ezlog.Debug().N(prefix).M("Found IHDR chunk").Out()
-		t.isPNG = true
+		// CHECK 2: 4byte header[12:16] - chunk type IHDR
+		t.isPNG = t.isPNG && bytes.Equal([]byte("IHDR"), t.Buf[12:16])
 	}
-
 	if t.isPNG {
+		ezlog.Debug().N(prefix).M("Found IHDR chunk").Out()
 		t.info()
 	}
 

p2i/version.go

@@ -23,5 +23,5 @@ THE SOFTWARE.
 package p2i
 
 const (
-	Version = "v2.0.4"
+	Version = "v2.0.5"
 )