qubes.GetImageRGBA: fix SVG conversion for images without explicit dimensions

SVGs without explicit width/height cause gm identify to report 0x0.
Pass those dimensions to rsvg-convert only when they are non-zero;
otherwise let rsvg-convert render at the SVG's natural size.

Re-read the actual dimensions from the rendered PNG afterwards so the
forcemaxsize downscale check and the final gm convert use correct values.

Replace echo+cut with read -r for dimension parsing throughout.

Author: Jayant-kernel

qubes-rpc/qubes.GetImageRGBA

@@ -21,22 +21,23 @@ elif ! [ -r "${filename}" ]; then
     exit 1
 fi
 
-s="$(gm identify -format '%w %h %m' "$filename")"
-w="$(echo "$s"|cut -d " " -f 1)"
-h="$(echo "$s"|cut -d " " -f 2)"
-m="$(echo "$s"|cut -d " " -f 3)"
+gm identify -format '%w %h %m' "$filename" | read -r w h m
 if [ "$m" = SVG ]; then
     tmpfile2="$(mktemp /tmp/qimg-XXXXXXXX.png)"
-    rsvg-convert -w "$w" -h "$h" -o "$tmpfile2" "$filename"
+    if [ -n "$w" ] && [ "$w" -gt 0 ] && [ -n "$h" ] && [ "$h" -gt 0 ]; then
+        rsvg-convert -w "$w" -h "$h" -o "$tmpfile2" "$filename"
+    else
+        rsvg-convert -o "$tmpfile2" "$filename"
+        # re-read dimensions from the rendered PNG since SVG had no explicit size
+        gm identify -format '%w %h' -- "$tmpfile2" | read -r w h
+    fi
     # downscale the image if necessary
     if [ -n "$forcemaxsize" ] && \
             { [ "$w" -gt "$forcemaxsize" ] || [ "$h" -gt "$forcemaxsize" ]; }; then
         gm convert "$tmpfile2" -scale "${forcemaxsize}x${forcemaxsize}" "$tmpfile2"
     fi
     # read the size again, because icon may not be a square or could have changed with convert
-    s="$(gm identify -format '%w %h' "$tmpfile2")"
-    w="$(echo "$s"|cut -d " " -f 1)"
-    h="$(echo "$s"|cut -d " " -f 2)"
+    gm identify -format '%w %h' -- "$tmpfile2" | read -r w h
     filename="$tmpfile2"
 fi
 echo "$w $h"