tests: rework handling of temp output files

Many of the tests open files in local paths for writing which leaves a
variety of temp files in the tests subdirs.  This ends up failing in a
few scenarios like out of tree builds or cmake builds.

Add a few helper functions to the common gdtest module to quickly get
handles to temp files for the tests to leverage.

1 files changed, 3 insertions, 7 deletions

diff --git a/tests/wbmp/wbmp_im2im.c b/tests/wbmp/wbmp_im2im.c
index 826c7fa..597f602 100644
--- a/tests/wbmp/wbmp_im2im.c
+++ b/tests/wbmp/wbmp_im2im.c
@@ -21,13 +21,9 @@ int main()
 	gdImageEllipse(src, 70, 25, 30, 20, b);
 
 #define OUTPUT_WBMP(name) do {							\
-		FILE *fp;										\
-														\
-		fp = fopen("wbmp_im2im_" #name ".wbmp", "wb");	\
-		if (fp) {										\
-			gdImageWBMP(name, 1, fp);					\
-			fclose(fp);									\
-		}												\
+		FILE *fp = gdTestTempFp();						\
+		gdImageWBMP(name, 1, fp);						\
+		fclose(fp);										\
 	} while (0)
 
 	OUTPUT_WBMP(src);