[i-g-t 3/4] lib/igt_core: Modify file opening logic to use IMGDIR environment variable

[Naladala Ramanaidu]

Modified __igt_fopen_data function to enhance file opening logic by
incorporating the IMGDIR environment variable.

- Added a new variable 'abpath' to store the value of IMGDIR.
- Updated the path construction to use IMGDIR if available.
- Implemented a fallback mechanism to use igt_datadir if the file is
  not found in IMGDIR.
- Ensured the existing fallback to igt_srcdir remains intact.

Signed-off-by: Naladala Ramanaidu <ramanaidu.naladala at intel.com>
---
 lib/igt_core.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/igt_core.c b/lib/igt_core.c
index 3ff3e0392..9b11c0850 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -3241,9 +3241,15 @@ FILE *__igt_fopen_data(const char* igt_srcdir, const char* igt_datadir,
 {
 	char path[PATH_MAX];
 	FILE *fp;
+	char *abpath;
 
-	snprintf(path, sizeof(path), "%s/%s", igt_datadir, filename);
+	abpath = getenv("IMGDIR");
+	snprintf(path, sizeof(path), "%s/%s", abpath, filename);
 	fp = fopen(path, "r");
+	if (!fp) {
+		snprintf(path, sizeof(path), "%s/%s", igt_datadir, filename);
+		fp = fopen(path, "r");
+	}
 	if (!fp) {
 		snprintf(path, sizeof(path), "%s/%s", igt_srcdir, filename);
 		fp = fopen(path, "r");
-- 
2.43.0