FindGIF: Add test

This tests whether GIFLIB can be found and the linker works. For newer
versions (>=5) it also tests if the version was parsed correctly.

1 files changed, 35 insertions, 0 deletions

diff --git a/Tests/FindGIF/Test/main.c b/Tests/FindGIF/Test/main.c
new file mode 100644
index 0000000..4ed72ec
--- /dev/null
+++ b/Tests/FindGIF/Test/main.c
@@ -0,0 +1,35 @@
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <gif_lib.h>
+
+// GIFLIB before version 5 didn't know this macro
+#ifndef GIFLIB_MAJOR
+#  define GIFLIB_MAJOR 4
+#endif
+
+int main()
+{
+  // because of the API changes we have to test different functions depending
+  // on the version of GIFLIB
+#if GIFLIB_MAJOR >= 5
+  // test the linker
+  GifErrorString(D_GIF_SUCCEEDED);
+
+  // check the version
+  char gif_version_string[16];
+  snprintf(gif_version_string, 16, "%i.%i.%i", GIFLIB_MAJOR, GIFLIB_MINOR,
+           GIFLIB_RELEASE);
+
+  assert(strcmp(gif_version_string, CMAKE_EXPECTED_GIF_VERSION) == 0);
+#else
+  // test the linker
+  GifLastError();
+
+  // unfortunately there is no way to check the version in older version of
+  // GIFLIB
+#endif
+
+  return 0;
+}