Let's have a sane error message here instead of some cryptic zlib error

diff --git a/ext/gd/libgd/gd_png.c b/ext/gd/libgd/gd_png.c
index 52a087e787418461a1ceaba9a8150586ae148861..1af49308c579fc75bc665c9efd7dd50081adc5eb 100644 (file)
--- a/ext/gd/libgd/gd_png.c
+++ b/ext/gd/libgd/gd_png.c
@@ -515,6 +515,10 @@ void gdImagePngCtxEx (gdImagePtr im, gdIOCtx * outfile, int level, int basefilte
        /*  png_set_filter(png_ptr, 0, PNG_FILTER_NONE);  */
 
        /* 2.0.12: this is finally a parameter */
+       if (level < 0 || level > 9) {
+               php_gd_error("gd-png error: compression level must be between 0 and 9");
+               return;
+       }
        png_set_compression_level(png_ptr, level);
        if (basefilter >= 0) {
                png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, basefilter);