Fix #72696: imagefilltoborder stackoverflow on truecolor images

We must not allow negative color values be passed to
gdImageFillToBorder(), because that can lead to infinite recursion
since the recursion termination condition will not necessarily be met.
void gdImageCopyResized (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, int srcX, int srcY, int dstW, int dstH, int srcW, int srcH)
{
	int c;
	int x, y;
	int tox, toy;
	int ydest;
	int i;
	int colorMap[gdMaxColors];
	/* Stretch vectors */
	int *stx, *sty;

	if (overflow2(sizeof(int), srcW)) {
		return;
	}
	if (overflow2(sizeof(int), srcH)) {
		return;
	}

	stx = (int *) gdMalloc (sizeof (int) * srcW);
	sty = (int *) gdMalloc (sizeof (int) * srcH);

	/* Fixed by Mao Morimoto 2.0.16 */
	for (i = 0; (i < srcW); i++) {
		stx[i] = dstW * (i+1) / srcW - dstW * i / srcW ;
	}
	for (i = 0; (i < srcH); i++) {
		sty[i] = dstH * (i+1) / srcH - dstH * i / srcH ;
	}
	for (i = 0; (i < gdMaxColors); i++) {
		colorMap[i] = (-1);
	}
	toy = dstY;
	for (y = srcY; (y < (srcY + srcH)); y++) {
		for (ydest = 0; (ydest < sty[y - srcY]); ydest++) {
			tox = dstX;
			for (x = srcX; (x < (srcX + srcW)); x++) {
				int nc = 0;
				int mapTo;
				if (!stx[x - srcX]) {
					continue;
				}
				if (dst->trueColor) {
					/* 2.0.9: Thorben Kundinger: Maybe the source image is not a truecolor image */
					if (!src->trueColor) {
					  	int tmp = gdImageGetPixel (src, x, y);
		  				mapTo = gdImageGetTrueColorPixel (src, x, y);
					  	if (gdImageGetTransparent (src) == tmp) {
							/* 2.0.21, TK: not tox++ */
							tox += stx[x - srcX];
					  		continue;
					  	}
					} else {
						/* TK: old code follows */
					  	mapTo = gdImageGetTrueColorPixel (src, x, y);
						/* Added 7/24/95: support transparent copies */
						if (gdImageGetTransparent (src) == mapTo) {
							/* 2.0.21, TK: not tox++ */
							tox += stx[x - srcX];
							continue;
						}
					}
				} else {
					c = gdImageGetPixel (src, x, y);
					/* Added 7/24/95: support transparent copies */
					if (gdImageGetTransparent (src) == c) {
					      tox += stx[x - srcX];
					      continue;
					}
					if (src->trueColor) {
					      /* Remap to the palette available in the destination image. This is slow and works badly. */
					      mapTo = gdImageColorResolveAlpha(dst, gdTrueColorGetRed(c),
					      					    gdTrueColorGetGreen(c),
					      					    gdTrueColorGetBlue(c),
					      					    gdTrueColorGetAlpha (c));
					} else {
						/* Have we established a mapping for this color? */
						if (colorMap[c] == (-1)) {
							/* If it's the same image, mapping is trivial */
							if (dst == src) {
								nc = c;
							} else {
								/* Find or create the best match */
								/* 2.0.5: can't use gdTrueColorGetRed, etc with palette */
								nc = gdImageColorResolveAlpha(dst, gdImageRed(src, c),
												   gdImageGreen(src, c),
												   gdImageBlue(src, c),
												   gdImageAlpha(src, c));
							}
							colorMap[c] = nc;
						}
						mapTo = colorMap[c];
					}
				}
				for (i = 0; (i < stx[x - srcX]); i++) {
					gdImageSetPixel (dst, tox, toy, mapTo);
					tox++;
				}
			}
			toy++;
		}
	}
	gdFree (stx);
	gdFree (sty);
}

void gdImageCopyResized (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, int srcX, int srcY, int dstW, int dstH, int srcW, int srcH)
{
	int c;
	int x, y;
	int tox, toy;
	int ydest;
	int i;
	int colorMap[gdMaxColors];
	/* Stretch vectors */
	int *stx, *sty;

	if (overflow2(sizeof(int), srcW)) {
		return;
	}
	if (overflow2(sizeof(int), srcH)) {
		return;
	}

	stx = (int *) gdMalloc (sizeof (int) * srcW);
	sty = (int *) gdMalloc (sizeof (int) * srcH);

	/* Fixed by Mao Morimoto 2.0.16 */
	for (i = 0; (i < srcW); i++) {
		stx[i] = dstW * (i+1) / srcW - dstW * i / srcW ;
	}
	for (i = 0; (i < srcH); i++) {
		sty[i] = dstH * (i+1) / srcH - dstH * i / srcH ;
	}
	for (i = 0; (i < gdMaxColors); i++) {
		colorMap[i] = (-1);
	}
	toy = dstY;
	for (y = srcY; (y < (srcY + srcH)); y++) {
		for (ydest = 0; (ydest < sty[y - srcY]); ydest++) {
			tox = dstX;
			for (x = srcX; (x < (srcX + srcW)); x++) {
				int nc = 0;
				int mapTo;
				if (!stx[x - srcX]) {
					continue;
				}
				if (dst->trueColor) {
					/* 2.0.9: Thorben Kundinger: Maybe the source image is not a truecolor image */
					if (!src->trueColor) {
					  	int tmp = gdImageGetPixel (src, x, y);
		  				mapTo = gdImageGetTrueColorPixel (src, x, y);
					  	if (gdImageGetTransparent (src) == tmp) {
							/* 2.0.21, TK: not tox++ */
							tox += stx[x - srcX];
					  		continue;
					  	}
					} else {
						/* TK: old code follows */
					  	mapTo = gdImageGetTrueColorPixel (src, x, y);
						/* Added 7/24/95: support transparent copies */
						if (gdImageGetTransparent (src) == mapTo) {
							/* 2.0.21, TK: not tox++ */
							tox += stx[x - srcX];
							continue;
						}
					}
				} else {
					c = gdImageGetPixel (src, x, y);
					/* Added 7/24/95: support transparent copies */
					if (gdImageGetTransparent (src) == c) {
					      tox += stx[x - srcX];
					      continue;
					}
					if (src->trueColor) {
					      /* Remap to the palette available in the destination image. This is slow and works badly. */
					      mapTo = gdImageColorResolveAlpha(dst, gdTrueColorGetRed(c),
					      					    gdTrueColorGetGreen(c),
					      					    gdTrueColorGetBlue(c),
					      					    gdTrueColorGetAlpha (c));
					} else {
						/* Have we established a mapping for this color? */
						if (colorMap[c] == (-1)) {
							/* If it's the same image, mapping is trivial */
							if (dst == src) {
								nc = c;
							} else {
								/* Find or create the best match */
								/* 2.0.5: can't use gdTrueColorGetRed, etc with palette */
								nc = gdImageColorResolveAlpha(dst, gdImageRed(src, c),
												   gdImageGreen(src, c),
												   gdImageBlue(src, c),
												   gdImageAlpha(src, c));
							}
							colorMap[c] = nc;
						}
						mapTo = colorMap[c];
					}
				}
				for (i = 0; (i < stx[x - srcX]); i++) {
					gdImageSetPixel (dst, tox, toy, mapTo);
					tox++;
				}
			}
			toy++;
		}
	}
	gdFree (stx);
	gdFree (sty);
}
