ext/gd: Fix imagewebp() return value for palette images

NEWS

@@ -202,6 +202,7 @@ PHP                                                                        NEWS
     (DanielEScherzer, cmb)
   . Fixed undefined behavior with GIFs with problematic LZW compression data.
     (DanielEScherzer, vapier)
+  . Fixed the return value of imagewebp() for palette images. (arshidkv12)
 
 - Intl:
   . Fixed IntlDateFormatter::parse(), localtime() and parseToCalendar()

ext/gd/gd.c

@@ -2009,7 +2009,10 @@ PHP_FUNCTION(imagewebp)
 		RETURN_THROWS();
 	}
 
-	gdImageWebpCtx(im, ctx, (int) quality);
+	if (!gdImageWebpCtxEx(im, ctx, (int) quality)) {
+		ctx->gd_free(ctx);
+		RETURN_FALSE;
+	}
 
 	ctx->gd_free(ctx);
 

ext/gd/libgd/gd.h

@@ -48,6 +48,7 @@ extern "C" {
 
 /* va_list needed in gdErrorMethod */
 #include <stdarg.h>
+#include <stdbool.h>
 
 /* The maximum number of palette entries in palette-based images.
 	In the wonderful new world of gd 2.0, you can of course have
@@ -633,6 +634,7 @@ void gdImageJpegCtx(gdImagePtr im, gdIOCtx *out, int quality);
 #define gdWebpLossless 101
 
 void gdImageWebpCtx (gdImagePtr im, gdIOCtx * outfile, int quality);
+bool gdImageWebpCtxEx (gdImagePtr im, gdIOCtx * outfile, int quality);
 
 /* Best to free this memory with gdFree(), not free() */
 void *gdImageJpegPtr(gdImagePtr im, int *size, int quality);

ext/gd/libgd/gd_webp.c

@@ -101,7 +101,11 @@ gdImagePtr gdImageCreateFromWebpCtx (gdIOCtx * infile)
 	return im;
 }
 
-void gdImageWebpCtx (gdImagePtr im, gdIOCtx * outfile, int quality)
+void gdImageWebpCtx(gdImagePtr im, gdIOCtx *outfile, int quality){
+    gdImageWebpCtxEx(im, outfile, quality);
+}
+
+bool gdImageWebpCtxEx (gdImagePtr im, gdIOCtx * outfile, int quality)
 {
 	uint8_t *argb;
 	int x, y;
@@ -110,29 +114,29 @@ void gdImageWebpCtx (gdImagePtr im, gdIOCtx * outfile, int quality)
 	size_t out_size;
 
 	if (im == NULL) {
-		return;
+		return false;
 	}
 
 	if (!gdImageTrueColor(im)) {
 		gd_error("Palette image not supported by webp");
-		return;
+		return false;
 	}
 
 	if (quality == -1) {
 		quality = 80;
 	}
 
 	if (overflow2(gdImageSX(im), 4)) {
-		return;
+		return false;
 	}
 
 	if (overflow2(gdImageSX(im) * 4, gdImageSY(im))) {
-		return;
+		return false;
 	}
 
 	argb = (uint8_t *)gdMalloc(gdImageSX(im) * 4 * gdImageSY(im));
 	if (!argb) {
-		return;
+		return false;
 	}
 	p = argb;
 	for (y = 0; y < gdImageSY(im); y++) {
@@ -165,9 +169,12 @@ void gdImageWebpCtx (gdImagePtr im, gdIOCtx * outfile, int quality)
 	}
 	gdPutBuf(out, out_size, outfile);
 	free(out);
+	gdFree(argb);
+	return true;
 
 freeargb:
 	gdFree(argb);
+	return false;
 }
 
 void gdImageWebpEx (gdImagePtr im, FILE * outFile, int quality)

ext/gd/tests/gh24457.phpt

@@ -0,0 +1,29 @@
+--TEST--
+imagewebp() with a palette image
+--EXTENSIONS--
+gd
+--SKIPIF--
+<?php
+if (!function_exists('imagewebp')) {
+    die('skip WebP support is not available');
+}
+?>
+--FILE--
+<?php
+$im = imagecreate(4, 4);
+var_dump(imagewebp($im, __DIR__ . '/imagewebp_palette.webp'));
+
+$im = imagecreatetruecolor(16384, 1);
+var_dump(imagewebp($im, __DIR__ . '/imagewebp_truecolor.webp'));
+?>
+--CLEAN--
+<?php
+@unlink(__DIR__ . '/imagewebp_palette.webp');
+@unlink(__DIR__ . '/imagewebp_truecolor.webp');
+?>
+--EXPECTF--
+Warning: imagewebp(): Palette image not supported by webp in %s on line %d
+bool(false)
+
+Warning: imagewebp(): gd-webp encoding failed in %s on line %d
+bool(false)