From f2beb0bc56fa574ef2252b781aa8236dc661cb67 Mon Sep 17 00:00:00 2001
From: OBattler <oubattler@gmail.com>
Date: Tue, 14 Jan 2020 20:53:39 +0100
Subject: [PATCH] Added a sanity check to the FDI2RAW code.

---
 src/floppy/fdi2raw.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/floppy/fdi2raw.c b/src/floppy/fdi2raw.c
index b42ca2f1d..ffb3c3a53 100644
--- a/src/floppy/fdi2raw.c
+++ b/src/floppy/fdi2raw.c
@@ -2029,6 +2029,10 @@ FDI *fdi2raw_header(FILE *f)
 	memset (fdi, 0, sizeof (FDI));
 	fdi->file = f;
 	oldseek = ftell (fdi->file);
+	if (oldseek == -1) {
+		fdi_free(fdi);
+		return NULL;
+	}
 	fseek (fdi->file, 0, SEEK_SET);
 	fread (fdi->header, 2048, 1, fdi->file);
 	fseek (fdi->file, oldseek, SEEK_SET);