https://imagemagick.org/discourse-server/viewtopic.php?f=3&t=35097

diff --git a/MagickWand/operation.c b/MagickWand/operation.c
index 8f60fbf676ac5e91f5cabc2d4d27b0f11a51d38d..17185bfe4f02cbd9e37cd32d8fa721ba0f6e940c 100644 (file)
--- a/MagickWand/operation.c
+++ b/MagickWand/operation.c
@@ -1239,11 +1239,11 @@ WandPrivate void CLISettingOptionInfo(MagickCLI *cli_wand,
     {
       if (LocaleCompare("quality",option+1) == 0)
         {
-          if (IsGeometry(arg1) == MagickFalse)
+          if (IfSetOption && (IsGeometry(arg1) == MagickFalse))
             CLIWandExceptArgBreak(OptionError,"InvalidArgument",option,arg1);
           _image_info->quality= IfSetOption ? StringToUnsignedLong(arg1)
                                             : UNDEFINED_COMPRESSION_QUALITY;
-          (void) SetImageOption(_image_info,option+1,ArgOption(NULL));
+          (void) SetImageOption(_image_info,option+1,ArgOption("0"));
           break;
         }
       if (LocaleCompare("quantize",option+1) == 0)