From 4e3e07d670b3021b489448621a508047bcf3523e Mon Sep 17 00:00:00 2001
From: Ted Unangst <tedu@tedunangst.com>
Date: Mon, 1 May 2023 15:32:36 -0400
Subject: [PATCH] svg image support

---
 backend.go  | 28 ++++++++++++++++++++++++++++
 database.go |  2 ++
 web.go      |  3 +++
 3 files changed, 33 insertions(+)

diff --git a/backend.go b/backend.go
index 81c67a8..2a9ac02 100644
--- a/backend.go
+++ b/backend.go
@@ -17,10 +17,13 @@ package main
 
 import (
 	"bytes"
+	"errors"
 	"net"
+	"net/http"
 	"net/rpc"
 	"os"
 	"os/exec"
+	"strings"
 
 	"humungus.tedunangst.com/r/webs/gate"
 	"humungus.tedunangst.com/r/webs/image"
@@ -55,7 +58,32 @@ func backendSockname() string {
 	return dataDir + "/backend.sock"
 }
 
+func isSVG(data []byte) bool {
+	ct := http.DetectContentType(data)
+	if strings.HasPrefix(ct, "text/xml") {
+		return strings.Index(string(data), "<!DOCTYPE svg PUBLIC") != -1
+	}
+	if strings.HasPrefix(ct, "text/plain") {
+		return bytes.HasPrefix(data, []byte("<svg "))
+	}
+	return ct == "image/svg+xml"
+}
+
+func imageFromSVG(data []byte) (*image.Image, error) {
+	if len(data) > 100000 {
+		return nil, errors.New("my svg is too big")
+	}
+	svg := &image.Image{
+		Data:   data,
+		Format: "svg+xml",
+	}
+	return svg, nil
+}
+
 func shrinkit(data []byte) (*image.Image, error) {
+	if isSVG(data) {
+		return imageFromSVG(data)
+	}
 	cl, err := rpc.Dial("unix", backendSockname())
 	if err != nil {
 		return nil, err
diff --git a/database.go b/database.go
index 263bbe5..a8a80a1 100644
--- a/database.go
+++ b/database.go
@@ -548,6 +548,8 @@ func savefileandxid(name string, desc string, url string, media string, local bo
 				xid += ".png"
 			case "image/jpeg":
 				xid += ".jpg"
+			case "image/svg+xml":
+				xid += ".svg"
 			case "application/pdf":
 				xid += ".pdf"
 			case "text/plain":
diff --git a/web.go b/web.go
index 1d0f3be..62e2200 100644
--- a/web.go
+++ b/web.go
@@ -1503,6 +1503,9 @@ func submitdonk(w http.ResponseWriter, r *http.Request) (*Donk, error) {
 		if format == "jpeg" {
 			format = "jpg"
 		}
+		if format == "svg+xml" {
+			format = "svg"
+		}
 		name = xfiltrate() + "." + format
 	} else {
 		ct := http.DetectContentType(data)