dom: fix crash on wrong image content type

+ slightly optimize getContentType

3 files changed, 10 insertions, 5 deletions

diff --git a/src/html/dom.nim b/src/html/dom.nim
index e58be7fc..20f21264 100644
--- a/src/html/dom.nim
+++ b/src/html/dom.nim
@@ -3035,12 +3035,15 @@ proc loadResource(window: Window; image: HTMLImageElement) =
           return newResolvedPromise()
         let response = res.get
         let contentType = response.getContentType("image/x-unknown")
-        if contentType.until('/') != "image":
+        if not contentType.startsWith("image/"):
           return newResolvedPromise()
         let cacheId = window.loader.addCacheFile(response.outputId,
           window.loader.clientPid)
+        let url = newURL("img-codec+" & contentType.after('/') & ":decode")
+        if url.isNone:
+          return newResolvedPromise()
         let request = newRequest(
-          newURL("img-codec+" & contentType.after('/') & ":decode").get,
+          url.get,
           httpMethod = hmPost,
           headers = newHeaders({"Cha-Image-Info-Only": "1"}),
           body = RequestBody(t: rbtOutput, outputId: response.outputId),
diff --git a/src/loader/response.nim b/src/loader/response.nim
index e97e931b..a3b7e3e4 100644
--- a/src/loader/response.nim
+++ b/src/loader/response.nim
@@ -97,9 +97,8 @@ func getCharset*(this: Response; fallback: Charset): Charset =
 
 func getContentType*(this: Response; fallback = "application/octet-stream"):
     string =
-  if "Content-Type" in this.headers.table:
-    let header = this.headers.table["Content-Type"][0].toLowerAscii()
-    return header.until(';').strip()
+  this.headers.table.withValue("Content-Type", p):
+    return p[][0].untilLower(';').strip()
   # also use DefaultGuess for container, so that local mime.types cannot
   # override buffer mime.types
   return DefaultGuess.guessContentType(this.url.pathname, fallback)
diff --git a/src/utils/twtstr.nim b/src/utils/twtstr.nim
index 81384eed..c41b545f 100644
--- a/src/utils/twtstr.nim
+++ b/src/utils/twtstr.nim
@@ -158,6 +158,9 @@ func untilLower*(s: string; c: set[char]; starti = 0): string =
 func until*(s: string; c: char; starti = 0): string =
   return s.until({c}, starti)
 
+func untilLower*(s: string; c: char; starti = 0): string =
+  return s.untilLower({c}, starti)
+
 func after*(s: string; c: set[char]): string =
   let i = s.find(c)
   if i != -1: