Check for non-empty image URL when handling RSS channel images

jq/convert/rss2cdf.jq

@@ -35,7 +35,7 @@ def parse_date: ensure_string | strptime("%a, %d %b %Y %T %Z") | mktime | todate
     | if $channel.lastBuildDate // $channel.pubDate then .["@LASTMOD"] = (
         $channel.lastBuildDate // $channel.pubDate | parse_date
     ) else . end
-    | if $channel.image then .LOGO = {
+    | if $channel.image and $channel.image.url then .LOGO = {
         "@HREF": $channel.image.url,
         "@STYLE": "IMAGE"
     } else . end

jq/convert/rss2echo.jq

@@ -62,7 +62,7 @@ def parse_date: ensure_string | strptime("%a, %d %b %Y %T %Z") | mktime | todate
         ]
     }
     | if $channel.language then .["@xml:lang"] = ($channel.language | ensure_string) else . end
-    | if $channel.image then .link += [{
+    | if $channel.image and $channel.image.url then .link += [{
         "@rel": "logo",
         # RSS does not provide an image's mime type, so we try to guess
         "@type": ("image/" + ($channel.image.url | capture("\\.(?<ext>[a-zA-Z0-9]+)$").ext // "x-unknown")),

jq/convert/rss2jsonfeed.jq

@@ -40,4 +40,4 @@ def ensure_array: (. // []) | if type == "array" then . else [.] end;
 # Optional language
 | if $channel.language then .language = $channel.language else . end
 # Optional icon
-| if $channel.image then .icon = $channel.image.url else . end
+| if $channel.image and $channel.image.url then .icon = $channel.image.url else . end