Fix tests based on coverity reports (#819)

* Partial #818, unused arg

* Partial #818, init var

* partail #818, fix va_args usage

* partail #818, handle f* calls and avoid possible call to malloc with negative values

* partail #818, prevent double free

* partail #818, resource leak if test fail

* partail #818, null deref fix

* partail #818, avoid double free on fp failure

* Partial #818, fix error msg

* Partial #818, leak on error

* Partial #818, null deref

* Partial #818, avoid possible negative index on failure

* partial #818, does not free if we return if requested new size overflow

* partial #818, avoid double free, free where the alloc happened

11 files changed, 62 insertions, 40 deletions

diff --git a/examples/nnquant.c b/examples/nnquant.c
index 82e3672..5ce104e 100644
--- a/examples/nnquant.c
+++ b/examples/nnquant.c
@@ -18,18 +18,17 @@ int main()
 {
 	gdImagePtr im, im2;
 	FILE *fp;
-	char path[2048];
 
 	fp=fopen("resampledbug.jpeg", "rb");
 	if (!fp) {
-		fprintf(stderr, "Can't load /home/pierre/IM3801.jpg\n");
+		fprintf(stderr, "Can't load resampledbug.jpeg\n");
 		return 1;
 	}
 
 	im = gdImageCreateFromJpeg(fp);
 	fclose(fp);
 	if (!im) {
-		fprintf(stderr, "Can't load TIFF image %s\n", path);
+		fprintf(stderr, "Can't decode JPEG image resampledbug.jpeg\n");
 		return 1;
 	}
 
diff --git a/src/gd.c b/src/gd.c
index d78504e..95aeabb 100644
--- a/src/gd.c
+++ b/src/gd.c
@@ -3831,12 +3831,12 @@ static void gdImageSetAAPixelColor(gdImagePtr im, int x, int y, int color, int t
  */
 BGD_DECLARE(void) gdImageSetStyle (gdImagePtr im, int *style, int noOfPixels)
 {
-	if (im->style) {
-		gdFree (im->style);
-	}
 	if (overflow2(sizeof (int), noOfPixels)) {
 		return;
 	}
+	if (im->style) {
+		gdFree (im->style);
+	}
 	im->style = (int *) gdMalloc (sizeof (int) * noOfPixels);
 	if (!im->style) {
 		return;
diff --git a/tests/gd2/gd2_read.c b/tests/gd2/gd2_read.c
index 9f2b808..be625c3 100644
--- a/tests/gd2/gd2_read.c
+++ b/tests/gd2/gd2_read.c
@@ -3,7 +3,7 @@
 #include <stdlib.h>
 #include "gdtest.h"
 
-int main(int argc, char *argv[])
+int main()
 {
 	int error = 0, i = 0;
 	gdImagePtr im, exp;
@@ -27,6 +27,9 @@ int main(int argc, char *argv[])
 			return 1;
 		}
 		im = gdImageCreateFromGd2(fp);
+		if (gdTestAssert(im == NULL)) {
+			gdTestErrorMsg("failed, cannot decode file: %s\n", path[0]);
+		}
 		fclose(fp);
 
 		if (path_exp[i] != NULL) {
diff --git a/tests/gd2/gd2_read_corrupt.c b/tests/gd2/gd2_read_corrupt.c
index 7afc303..a636316 100644
--- a/tests/gd2/gd2_read_corrupt.c
+++ b/tests/gd2/gd2_read_corrupt.c
@@ -4,7 +4,7 @@
 #include <stdlib.h>
 #include "gdtest.h"
 
-int main(int argc, char *argv[])
+int main()
 {
 	gdImagePtr im;
 	FILE *fp;
diff --git a/tests/gdimagecolorexact/gdimagecolorexact.c b/tests/gdimagecolorexact/gdimagecolorexact.c
index 9d754ca..e127b84 100644
--- a/tests/gdimagecolorexact/gdimagecolorexact.c
+++ b/tests/gdimagecolorexact/gdimagecolorexact.c
@@ -30,34 +30,32 @@ int main()
 	c3 = gdImageColorExactAlpha(im, 255, 0, 255, 100);
 	c4 = gdImageColorExactAlpha(im, 255, 34, 255, 100);
 
+
 	if (gdTestAssert(c1 == 0) != 1) {
-		error = -1;
+		color = gdTrueColorAlpha(gdImageRed(im, c1), gdImageGreen(im, c1),
+								gdImageBlue(im, c1), 0);
+		if (gdTestAssert(color == 0xFF00FF) != 1) {
+			error = -1;
+		}
 	}
 	if (gdTestAssert(c2 == 1) != 1) {
-		error = -1;
+		color = gdTrueColorAlpha(gdImageRed(im, c2), gdImageGreen(im, c2),
+								gdImageBlue(im, c2), 0);
+		if (gdTestAssert(color == 0xFFC800) != 1) {
+			error = -1;
+		}
 	}
 	if (gdTestAssert(c3 == 2) != 1) {
-		error = -1;
+		color = gdTrueColorAlpha(gdImageRed(im, c3), gdImageGreen(im, c3),
+								gdImageBlue(im, c3), 0);
+		if (gdTestAssert(color == 0xFF00FF) != 1) {
+			error = -1;
+		}
 	}
 	if (gdTestAssert(c4 == -1) != 1) {
 		error = -1;
 	}
 
-	color = gdTrueColorAlpha(gdImageRed(im, c1), gdImageGreen(im, c1),
-	                         gdImageBlue(im, c1), 0);
-	if (gdTestAssert(color == 0xFF00FF) != 1) {
-		error = -1;
-	}
-	color = gdTrueColorAlpha(gdImageRed(im, c2), gdImageGreen(im, c2),
-	                         gdImageBlue(im, c2), 0);
-	if (gdTestAssert(color == 0xFFC800) != 1) {
-		error = -1;
-	}
-	color = gdTrueColorAlpha(gdImageRed(im, c3), gdImageGreen(im, c3),
-	                         gdImageBlue(im, c3), 0);
-	if (gdTestAssert(color == 0xFF00FF) != 1) {
-		error = -1;
-	}
 	gdImageDestroy(im);
 
 	return error;
diff --git a/tests/gdimagefill/bug00002_1.c b/tests/gdimagefill/bug00002_1.c
index 3a66d7b..d348f0b 100644
--- a/tests/gdimagefill/bug00002_1.c
+++ b/tests/gdimagefill/bug00002_1.c
@@ -21,13 +21,14 @@ int main()
 
 	file = gdTestTempFile("bug00002_1.png");
 	fp = fopen(file, "wb");
-	free(file);
+
 	if (fp == NULL) {
 		gdTestErrorMsg("Cannot create image from <%s>\n", file);
+		free(file);
 		gdImageDestroy(im);
 		return 1;
 	}
-
+	free(file);
 	gdImagePng(im,fp);
 	fclose(fp);
 
diff --git a/tests/gdimagescatterex/bug00208_2.c b/tests/gdimagescatterex/bug00208_2.c
index 58c1382..8c3df28 100644
--- a/tests/gdimagescatterex/bug00208_2.c
+++ b/tests/gdimagescatterex/bug00208_2.c
@@ -7,7 +7,7 @@ int main()
 	FILE *fp;
 	gdScatter s;
 	int colors[] = {0xFF0000, 0x00FF00};
-	CuTestImageResult r;
+	CuTestImageResult r = {0,0};
 
 	fp = gdTestFileOpen("gdimagescatterex/bug00208.png");
 	im = gdImageCreateFromPng(fp);
diff --git a/tests/gdtest/gdtest.c b/tests/gdtest/gdtest.c
index 69efda0..72b3758 100644
--- a/tests/gdtest/gdtest.c
+++ b/tests/gdtest/gdtest.c
@@ -396,6 +396,7 @@ FILE *gdTestTempFp(void)
 	FILE *fp = fopen(file, "wb");
 	if (fp == NULL) {
 		printf("fail to open tmp file");
+		free(file);
 		return NULL;
 	}
 	free(file);
@@ -425,6 +426,7 @@ char *gdTestFilePathV(const char *path, va_list args)
 		return NULL;
 	}
 	strcpy(file, GDTEST_TOP_DIR);
+
 	p = path;
 	do {
 #if defined(_WIN32) && !defined(__MINGW32__) &&  !defined(__MINGW64__)
@@ -435,7 +437,6 @@ char *gdTestFilePathV(const char *path, va_list args)
 		strcat(file, p);
 
 	} while ((p = va_arg(args, const char *)) != NULL);
-	va_end(args);
 
 	return file;
 }
@@ -443,8 +444,11 @@ char *gdTestFilePathV(const char *path, va_list args)
 char *gdTestFilePathX(const char *path, ...)
 {
 	va_list args;
+	char *res;
 	va_start(args, path);
-	return gdTestFilePathV(path, args);
+	res = gdTestFilePathV(path, args);
+	va_end(args);
+	return res;
 }
 
 FILE *gdTestFileOpenX(const char *path, ...)
@@ -458,9 +462,12 @@ FILE *gdTestFileOpenX(const char *path, ...)
 	fp = fopen(file, "rb");
 	if (fp == NULL) {
 		printf("failed to open path (rb).");
+		free(file);
+		va_end(args);
 		return NULL;
 	}
 	free(file);
+	va_end(args);
 	return fp;
 }
 
@@ -606,6 +613,7 @@ int gdTestImageCompareToImage(const char* file, unsigned int line, const char* m
 	}
 
 	surface_diff = gdImageCreateTrueColor(width_a, height_a);
+	if (surface_diff == NULL) goto fail;
 
 	gdTestImageDiff(expected, actual, surface_diff, &result);
 	if (result.pixels_changed>0) {
@@ -636,7 +644,7 @@ int gdTestImageCompareToImage(const char* file, unsigned int line, const char* m
 		gdImagePng(surface_diff,fp);
 		fclose(fp);
 		gdImageDestroy(surface_diff);
-
+		surface_diff = NULL;
 		fp = fopen(file_out, "wb");
 		if (!fp) goto fail;
 		gdImagePng(actual, fp);
@@ -645,6 +653,7 @@ int gdTestImageCompareToImage(const char* file, unsigned int line, const char* m
 	} else {
 		if (surface_diff) {
 			gdImageDestroy(surface_diff);
+			surface_diff = NULL;
 		}
 		return 1;
 	}
diff --git a/tests/tga/bug00084.c b/tests/tga/bug00084.c
index 7d4ca92..3cf0710 100644
--- a/tests/tga/bug00084.c
+++ b/tests/tga/bug00084.c
@@ -7,7 +7,13 @@ int main()
 {
     gdImagePtr im;
     FILE *fp = gdTestFileOpen("tga/bug00084.tga");
+    if (gdTestAssert(fp == NULL)) {
+        return 1;
+    }
     im = gdImageCreateFromTga(fp);
-	gdImageDestroy(im);
+    fclose(fp);
+    if (gdTestAssert(im != NULL)) {
+        gdImageDestroy(im);
+    }
     return 0;
 }
diff --git a/tests/tga/heap_overflow.c b/tests/tga/heap_overflow.c
index ddd4b63..119eb23 100644
--- a/tests/tga/heap_overflow.c
+++ b/tests/tga/heap_overflow.c
@@ -28,7 +28,9 @@ static void check_file(char *basename)
 
     size = read_test_file(&buffer, basename);
     im = gdImageCreateFromTgaPtr(size, (void *) buffer);
-    gdTestAssert(im == NULL);
+    if (!gdTestAssert(im == NULL)) {
+        gdImageDestroy(im);
+    }
     free(buffer);
 }
 
diff --git a/tests/tiff/tiff_invalid_read.c b/tests/tiff/tiff_invalid_read.c
index bed5389..7acf7cf 100644
--- a/tests/tiff/tiff_invalid_read.c
+++ b/tests/tiff/tiff_invalid_read.c
@@ -25,13 +25,15 @@ int main()
 static void check_file(char *basename)
 {
     gdImagePtr im;
-    char *buffer;
+    char *buffer = NULL;
     size_t size;
 
     size = read_test_file(&buffer, basename);
     im = gdImageCreateFromTiffPtr(size, (void *) buffer);
     gdTestAssert(im == NULL);
-    free(buffer);
+    if (buffer != NULL) {
+        free(buffer);
+    }
 }
 
 
@@ -43,18 +45,20 @@ static size_t read_test_file(char **buffer, char *basename)
 
     filename = gdTestFilePath2("tiff", basename);
     fp = fopen(filename, "rb");
-    gdTestAssert(fp != NULL);
+    if (gdTestAssert(fp != NULL)) goto fail3;
 
-	fseek(fp, 0, SEEK_END);
+	if (fseek(fp, 0, SEEK_END) != 0) goto fail2;
 	exp_size = ftell(fp);
-	fseek(fp, 0, SEEK_SET);
+	if (fseek(fp, 0, SEEK_SET) != 0) goto fail2;
 
     *buffer = malloc(exp_size);
-    gdTestAssert(*buffer != NULL);
+    if (gdTestAssert(*buffer != NULL)) goto fail2;
     act_size = fread(*buffer, sizeof(**buffer), exp_size, fp);
     gdTestAssert(act_size == exp_size);
 
+fail2:
     fclose(fp);
+fail3:
     free(filename);
 
     return act_size;