Fix for bug #45030

rlerdorf · rlerdorf · commit a3383ac3d7e2 · 2008-07-31T09:23:18.000Z
diff --git a/ext/gd/libgd/gd.c b/ext/gd/libgd/gd.c
@@ -2620,6 +2620,7 @@ void gdImageCopyResampled (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, i
 				green /= spixels;
 				blue /= spixels;
 				alpha /= spixels;
+				alpha += 0.5;
 			}
 			if ( alpha_sum != 0.0f) {
 				if( contrib_sum != 0.0f) {
diff --git a/ext/gd/libgd/gd_png.c b/ext/gd/libgd/gd_png.c
@@ -689,7 +689,12 @@ void gdImagePngCtxEx (gdImagePtr im, gdIOCtx * outfile, int level, int basefilte
 					 */
 					a = gdTrueColorGetAlpha(thisPixel);
 					/* Andrew Hull: >> 6, not >> 7! (gd 2.0.5) */
-					*pOutputRow++ = 255 - ((a << 1) + (a >> 6));
+					if (a == 127) {
+						*pOutputRow++ = 0;
+					} else {
+						*pOutputRow++ = 255 - ((a << 1) + (a >> 6));
+					}
+
 				}
 			}
 		}

Original file line number	Diff line number	Diff line change
`@@ -2620,6 +2620,7 @@ void gdImageCopyResampled (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, i`
`2620`	`2620`	`green /= spixels;`
`2621`	`2621`	`blue /= spixels;`
`2622`	`2622`	`alpha /= spixels;`
	`2623`	`+ alpha += 0.5;`
`2623`	`2624`	`}`
`2624`	`2625`	`if ( alpha_sum != 0.0f) {`
`2625`	`2626`	`if( contrib_sum != 0.0f) {`
Original file line number	Diff line number	Diff line change
`@@ -689,7 +689,12 @@ void gdImagePngCtxEx (gdImagePtr im, gdIOCtx * outfile, int level, int basefilte`
`689`	`689`	`*/`
`690`	`690`	`a = gdTrueColorGetAlpha(thisPixel);`
`691`	`691`	`/* Andrew Hull: >> 6, not >> 7! (gd 2.0.5) */`
`692`		`- *pOutputRow++ = 255 - ((a << 1) + (a >> 6));`
	`692`	`+ if (a == 127) {`
	`693`	`+ *pOutputRow++ = 0;`
	`694`	`+ } else {`
	`695`	`+ *pOutputRow++ = 255 - ((a << 1) + (a >> 6));`
	`696`	`+ }`
	`697`	`+`
`693`	`698`	`}`
`694`	`699`	`}`
`695`	`700`	`}`