Fix: AddPictureFromBytes fails on SVG (image: unknown format)

go.mod

@@ -1,17 +1,17 @@
 module github.com/xuri/excelize/v2
 
-go 1.24.0
+go 1.23.3
 
 require (
 	github.com/richardlehane/mscfb v1.0.4
 	github.com/stretchr/testify v1.11.1
 	github.com/tiendc/go-deepcopy v1.7.1
 	github.com/xuri/efp v0.0.1
 	github.com/xuri/nfp v0.0.2-0.20250530014748-2ddeb826f9a9
-	golang.org/x/crypto v0.43.0
+	golang.org/x/crypto v0.41.0
 	golang.org/x/image v0.25.0
-	golang.org/x/net v0.46.0
-	golang.org/x/text v0.30.0
+	golang.org/x/net v0.43.0
+	golang.org/x/text v0.28.0
 )
 
 require (

go.sum

@@ -15,12 +15,15 @@ github.com/xuri/efp v0.0.1 h1:fws5Rv3myXyYni8uwj2qKjVaRP30PdjeYe2Y6FDsCL8=
 github.com/xuri/efp v0.0.1/go.mod h1:ybY/Jr0T0GTCnYjKqmdwxyxn2BQf2RcQIIvex5QldPI=
 github.com/xuri/nfp v0.0.2-0.20250530014748-2ddeb826f9a9 h1:+C0TIdyyYmzadGaL/HBLbf3WdLgC29pgyhTjAT/0nuE=
 github.com/xuri/nfp v0.0.2-0.20250530014748-2ddeb826f9a9/go.mod h1:WwHg+CVyzlv/TX9xqBFXEZAuxOPxn2k1GNHwG41IIUQ=
+golang.org/x/crypto v0.41.0/go.mod h1:pO5AFd7FA68rFak7rOAGVuygIISepHftHnr8dr6+sUc=
 golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
 golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
 golang.org/x/image v0.25.0 h1:Y6uW6rH1y5y/LK1J8BPWZtr6yZ7hrsy6hFrXjgsc2fQ=
 golang.org/x/image v0.25.0/go.mod h1:tCAmOEGthTtkalusGp1g3xa2gke8J6c2N565dTyl9Rs=
+golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
 golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
 golang.org/x/text v0.30.0 h1:yznKA/E9zq54KzlzBEAWn1NXSQ8DIp/NYMy88xJjl4k=
 golang.org/x/text v0.30.0/go.mod h1:yDdHFIX9t+tORqspjENWgzaCVXgk0yYnYuSZ8UzzBVM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=

picture.go

@@ -15,7 +15,9 @@ import (
 	"bytes"
 	"encoding/xml"
 	"image"
+	"image/color"
 	"io"
+	"math"
 	"os"
 	"path"
 	"path/filepath"
@@ -236,9 +238,19 @@ func (f *File) AddPictureFromBytes(sheet, cell string, pic *Picture) error {
 		return ErrParameterInvalid
 	}
 	options := parseGraphicOptions(pic.Format)
-	img, _, err := image.DecodeConfig(bytes.NewReader(pic.File))
-	if err != nil {
-		return err
+	var img image.Config
+	if ext == ".svg" {
+		cfg, err := svgDecodeConfig(pic.File)
+		if err != nil {
+			return err
+		}
+		img = cfg
+	} else {
+		cfg, _, err := image.DecodeConfig(bytes.NewReader(pic.File))
+		if err != nil {
+			return err
+		}
+		img = cfg
 	}
 	// Read sheet data
 	f.mu.Lock()
@@ -286,6 +298,109 @@ func (f *File) AddPictureFromBytes(sheet, cell string, pic *Picture) error {
 	return err
 }
 
+// --- SVG helpers ---
+
+type svgRoot struct {
+	Width   string `xml:"width,attr"`
+	Height  string `xml:"height,attr"`
+	ViewBox string `xml:"viewBox,attr"`
+}
+
+// svgUnitToPx converts a numeric string with an optional unit suffix
+// (e.g. "16px", "12pt", "1in") to pixels using a 96-DPI scale,
+// which is the standard DPI for Office/Excel.
+func svgUnitToPx(s string) (float64, bool) {
+	s = strings.TrimSpace(s)
+	if s == "" {
+		return 0, false
+	}
+	i := len(s)
+	for i > 0 && (s[i-1] < '0' || s[i-1] > '9') && s[i-1] != '.' {
+		i--
+	}
+	num := strings.TrimSpace(s[:i])
+	unit := strings.ToLower(strings.TrimSpace(s[i:]))
+
+	v, err := strconv.ParseFloat(num, 64)
+	if err != nil {
+		return 0, false
+	}
+	switch unit {
+	case "", "px":
+		return v, true
+	case "pt":
+		return v * (96.0 / 72.0), true
+	case "in":
+		return v * 96.0, true
+	case "mm":
+		return v * (96.0 / 25.4), true
+	case "cm":
+		return v * (96.0 / 2.54), true
+	default:
+		return 0, false
+	}
+}
+
+// svgDecodeConfig extracts approximate image dimensions for SVG files
+// based on the <svg> element's width/height attributes or its viewBox.
+// Only the root <svg ...> element is parsed; the SVG content is not rendered.
+func svgDecodeConfig(b []byte) (image.Config, error) {
+	var root svgRoot
+	dec := xml.NewDecoder(bytes.NewReader(b))
+	dec.Strict = false
+	dec.AutoClose = xml.HTMLAutoClose
+	dec.Entity = xml.HTMLEntity
+
+	// Read only the root <svg> element and decode its attributes.
+	for {
+		tok, err := dec.Token()
+		if err != nil {
+			return image.Config{}, err
+		}
+		if se, ok := tok.(xml.StartElement); ok && strings.EqualFold(se.Name.Local, "svg") {
+			if err := dec.DecodeElement(&root, &se); err != nil && err != io.EOF {
+				return image.Config{}, err
+			}
+			break
+		}
+	}
+
+	// 1) Use width/height attributes if both are present and valid.
+	if wpx, okW := svgUnitToPx(root.Width); okW {
+		if hpx, okH := svgUnitToPx(root.Height); okH {
+			return image.Config{
+				ColorModel: color.RGBAModel,
+				Width:      int(math.Max(1, math.Round(wpx))),
+				Height:     int(math.Max(1, math.Round(hpx))),
+			}, nil
+		}
+	}
+
+	// 2) Otherwise, try to infer dimensions from the viewBox attribute:
+	//    "minX minY width height"
+	if root.ViewBox != "" {
+		parts := strings.Fields(root.ViewBox)
+		if len(parts) == 4 {
+			if vw, err1 := strconv.ParseFloat(parts[2], 64); err1 == nil && vw > 0 {
+				if vh, err2 := strconv.ParseFloat(parts[3], 64); err2 == nil && vh > 0 {
+					return image.Config{
+						ColorModel: color.RGBAModel,
+						Width:      int(math.Max(1, math.Round(vw))),
+						Height:     int(math.Max(1, math.Round(vh))),
+					}, nil
+				}
+			}
+		}
+	}
+
+	// 3) Fallback to a default icon-sized bounding box if nothing is specified.
+	return image.Config{
+		ColorModel: color.RGBAModel,
+		Width:      16,
+		Height:     16,
+	}, nil
+}
+
 // addSheetLegacyDrawing provides a function to add legacy drawing element to
 // xl/worksheets/sheet%d.xml by given worksheet name and relationship index.
 func (f *File) addSheetLegacyDrawing(sheet string, rID int) {