Fixed #596: gdTransformAffineCopy run error

And add test case for it.

8 files changed, 119 insertions, 16 deletions

diff --git a/src/gd_interpolation.c b/src/gd_interpolation.c
index 90d4a93..7d2ef57 100644
--- a/src/gd_interpolation.c
+++ b/src/gd_interpolation.c
@@ -1975,6 +1975,51 @@ BGD_DECLARE(int) gdTransformAffineGetImage(gdImagePtr *dst,
 	}
 }
 
+/** Function: getPixelRgbInterpolated
+ *   get the index of the image's colors
+ *
+ * Parameters:
+ *  im - Image to draw the transformed image
+ *  tcolor - TrueColor
+ *
+ * Return:
+ *  index of colors
+ */
+static int getPixelRgbInterpolated(gdImagePtr im, const int tcolor)
+{
+	unsigned char r, g, b, a;
+	int ct;
+
+	b = (unsigned char)tcolor;
+	g = (unsigned char)tcolor >> 8;
+	r = (unsigned char)tcolor >> 16;
+	a = (unsigned char)tcolor >> 24;
+
+	b = CLAMP(b, 0, 255);
+	g = CLAMP(g, 0, 255);
+	r = CLAMP(r, 0, 255);
+	a = CLAMP(a, 0, 127);
+
+	for (int i = 0; i < im->colorsTotal; i++) {
+	    if (im->red[i] == r && im->green[i] == g && im->blue[i] == b && im->alpha[i] == a) {
+			return i;
+		}
+	}
+
+	ct = im->colorsTotal;
+	if (ct == gdMaxColors) {
+		return -1;
+	}
+
+	im->colorsTotal++;
+	im->red[ct] = r;
+	im->green[ct] = g;
+	im->blue[ct] = b;
+	im->alpha[ct] = a;
+	im->open[ct] = 0;
+
+	return ct;
+}
 /**
  * Function: gdTransformAffineCopy
  *  Applies an affine transformation to a region and copy the result
@@ -2011,8 +2056,11 @@ BGD_DECLARE(int) gdTransformAffineCopy(gdImagePtr dst,
 		gdImageSetInterpolationMethod(src, GD_BICUBIC);
 	}
 
-
 	gdImageClipRectangle(src, src_region);
+	c1x = src_region->x;
+	c1y = src_region->y;
+	c2x = src_region->x + src_region->width -1;
+	c2y = src_region->y + src_region->height -1;
 
 	if (src_region->x > 0 || src_region->y > 0
 		|| src_region->width < gdImageSX(src)
@@ -2036,8 +2084,6 @@ BGD_DECLARE(int) gdTransformAffineCopy(gdImagePtr dst,
 		return GD_FALSE;
 	}
 
-	gdImageGetClip(dst, &c1x, &c1y, &c2x, &c2y);
-
 	end_x = bbox.width  + abs(bbox.x);
 	end_y = bbox.height + abs(bbox.y);
 
@@ -2053,18 +2099,24 @@ BGD_DECLARE(int) gdTransformAffineCopy(gdImagePtr dst,
 	if (dst->alphaBlendingFlag) {
 		for (y = bbox.y; y <= end_y; y++) {
 			pt.y = y + 0.5;
-			for (x = 0; x <= end_x; x++) {
+			for (x = bbox.x; x <= end_x; x++) {
 				pt.x = x + 0.5;
 				gdAffineApplyToPointF(&src_pt, &pt, inv);
-				gdImageSetPixel(dst, dst_x + x, dst_y + y, getPixelInterpolated(src, src_offset_x + src_pt.x, src_offset_y + src_pt.y, 0));
+				if (floor(src_offset_x + src_pt.x) < c1x
+					|| floor(src_offset_x + src_pt.x) > c2x
+					|| floor(src_offset_y + src_pt.y) < c1y
+					|| floor(src_offset_y + src_pt.y) > c2y) {
+					continue;
+				}
+				gdImageSetPixel(dst, dst_x + x, dst_y + y, getPixelInterpolated(src, (int)(src_offset_x + src_pt.x), (int)(src_offset_y + src_pt.y), 0));
 			}
 		}
 	} else {
-		for (y = 0; y <= end_y; y++) {
+		for (y = bbox.y; y <= end_y; y++) {
 			unsigned char *dst_p = NULL;
 			int *tdst_p = NULL;
 
-			pt.y = y + 0.5 + bbox.y;
+			pt.y = y + 0.5;
 			if ((dst_y + y) < 0 || ((dst_y + y) > gdImageSY(dst) -1)) {
 				continue;
 			}
@@ -2074,17 +2126,23 @@ BGD_DECLARE(int) gdTransformAffineCopy(gdImagePtr dst,
 				dst_p = dst->pixels[dst_y + y] + dst_x;
 			}
 
-			for (x = 0; x <= end_x; x++) {
-				pt.x = x + 0.5 + bbox.x;
+			for (x = bbox.x; x <= end_x; x++) {
+				pt.x = x + 0.5;
 				gdAffineApplyToPointF(&src_pt, &pt, inv);
 
 				if ((dst_x + x) < 0 || (dst_x + x) > (gdImageSX(dst) - 1)) {
 					break;
 				}
+				if (floor(src_offset_x + src_pt.x) < c1x
+					|| floor(src_offset_x + src_pt.x) > c2x
+					|| floor(src_offset_y + src_pt.y) < c1y
+					|| floor(src_offset_y + src_pt.y) > c2y) {
+					continue;
+				}
 				if (dst->trueColor) {
-					*(tdst_p++) = getPixelInterpolated(src, src_offset_x + src_pt.x, src_offset_y + src_pt.y, -1);
+					*(tdst_p + dst_x + x) = getPixelInterpolated(src, (int)(src_offset_x + src_pt.x), (int)(src_offset_y + src_pt.y), -1);
 				} else {
-					*(dst_p++) = getPixelInterpolated(src, src_offset_x + src_pt.x, src_offset_y + src_pt.y, -1);
+					*(dst_p + dst_x + x) = getPixelRgbInterpolated(dst, getPixelInterpolated(src, (int)(src_offset_x + src_pt.x), (int)(src_offset_y + src_pt.y), -1));
 				}
 			}
 		}
@@ -2148,8 +2206,8 @@ BGD_DECLARE(int) gdTransformAffineBoundingBox(gdRectPtr src, const double affine
 	}
 	bbox->x = (int) min.x;
 	bbox->y = (int) min.y;
-	bbox->width  = (int) ceil((max.x - min.x)) + 1;
-	bbox->height = (int) ceil(max.y - min.y) + 1;
+	bbox->width  = (int) ceil((max.x - min.x));
+	bbox->height = (int) ceil(max.y - min.y);
 
 	return GD_TRUE;
 }
diff --git a/src/gd_matrix.c b/src/gd_matrix.c
index 7d3fe35..ada63e6 100644
--- a/src/gd_matrix.c
+++ b/src/gd_matrix.c
@@ -63,7 +63,7 @@ BGD_DECLARE(int) gdAffineInvert (double dst[6], const double src[6])
 {
 	double r_det = (src[0] * src[3] - src[1] * src[2]);
 
-	if (r_det <= 0.0) {
+	if (fabs(r_det) <= 0.0) {
 		return GD_FALSE;
 	}
 
diff --git a/tests/gdimagerotate/php_bug_65070_exp.png b/tests/gdimagerotate/php_bug_65070_exp.png
index fba85f6..64b8b10 100644
--- a/tests/gdimagerotate/php_bug_65070_exp.png
+++ b/tests/gdimagerotate/php_bug_65070_exp.png
diff --git a/tests/gdtransformaffineboundingbox/github_bug_00221.c b/tests/gdtransformaffineboundingbox/github_bug_00221.c
index 4a50f73..9e75d0e 100644
--- a/tests/gdtransformaffineboundingbox/github_bug_00221.c
+++ b/tests/gdtransformaffineboundingbox/github_bug_00221.c
@@ -24,7 +24,7 @@ int main()
 		if (gdTransformAffineBoundingBox(&area, affine, &bbox) != GD_TRUE) {
 			return 1;
 		}
-		if (!(bbox.x ==-253 &&  bbox.y ==-228 && bbox.width == 298 && bbox.height == 230)) {
+		if (!(bbox.x ==-253 &&  bbox.y ==-228 && bbox.width == 297 && bbox.height == 229)) {
 			return 1;
 		}
 
diff --git a/tests/gdtransformaffinecopy/.gitignore b/tests/gdtransformaffinecopy/.gitignore
index 85e7fa0..2af21d5 100644
--- a/tests/gdtransformaffinecopy/.gitignore
+++ b/tests/gdtransformaffinecopy/.gitignore
@@ -1,3 +1,4 @@
 /github_bug_00583
 /github_bug_00585
 /github_bug_00586
+/github_bug_00596
diff --git a/tests/gdtransformaffinecopy/CMakeLists.txt b/tests/gdtransformaffinecopy/CMakeLists.txt
index f3475db..4af9fcc 100644
--- a/tests/gdtransformaffinecopy/CMakeLists.txt
+++ b/tests/gdtransformaffinecopy/CMakeLists.txt
@@ -2,6 +2,7 @@ LIST(APPEND TESTS_FILES
 	github_bug_00583
 	github_bug_00585
 	github_bug_00586
+	github_bug_00596
 )
 
 ADD_GD_TESTS()
diff --git a/tests/gdtransformaffinecopy/Makemodule.am b/tests/gdtransformaffinecopy/Makemodule.am
index 5541e8b..494ec80 100644
--- a/tests/gdtransformaffinecopy/Makemodule.am
+++ b/tests/gdtransformaffinecopy/Makemodule.am
@@ -1,7 +1,8 @@
 libgd_test_programs += \
 	gdtransformaffinecopy/github_bug_00583 \
 	gdtransformaffinecopy/github_bug_00585 \
-	gdtransformaffinecopy/github_bug_00586
+	gdtransformaffinecopy/github_bug_00586 \
+	gdtransformaffinecopy/github_bug_00596
 
 EXTRA_DIST += \
 	gdtransformaffinecopy/CMakeLists.txt
diff --git a/tests/gdtransformaffinecopy/github_bug_00596.c b/tests/gdtransformaffinecopy/github_bug_00596.c
new file mode 100644
index 0000000..51912e1
--- /dev/null
+++ b/tests/gdtransformaffinecopy/github_bug_00596.c
@@ -0,0 +1,42 @@
+/**
+ * Test gdTransformAffineCopy() run error
+ *
+ * See <https://github.com/libgd/libgd/issues/596>
+ *
+ */
+
+#include "gd.h"
+#include "gdtest.h"
+
+int main()
+{
+	double matrix[] = {1, 0, 0, 1, 0, 0};
+	gdImagePtr src, dst;
+	gdRect rect = {0, 0, 16, 16};
+	int white, green;
+	int status = 0;
+	int res;
+	int actual_color = 0;
+	int expected_color = 0x00ff00;
+
+	src = gdImageCreateTrueColor(16, 16);
+	gdTestAssert(src != NULL);
+	white = gdImageColorAllocate(src, 255, 255, 255);
+	gdImageFilledRectangle(src, 0, 0, 16, 16, white);
+
+	dst = gdImageCreateTrueColor(50, 50);
+	gdTestAssert(dst != NULL);
+	green = gdImageColorAllocate(dst, 0, 255, 0);
+	gdImageFilledRectangle(dst, 0, 0, 50, 50, green);
+
+	res = gdTransformAffineCopy(dst, 4, 4, src, &rect, matrix);
+	gdTestAssert(res != GD_FALSE);
+
+	status = gdNumFailures();
+	actual_color = gdImageGetPixel(dst, 20, 5);
+	status = (actual_color == expected_color) ? status : 1;
+
+	gdImageDestroy(src);
+	gdImageDestroy(dst);
+	return status;
+}