From e8824afa1ba9cec6b91428d991c6b0d9bc0c3877 Mon Sep 17 00:00:00 2001
From: Con Kolivas <kernel@kolivas.org>
Date: Fri, 22 Apr 2011 19:23:40 +1000
Subject: [PATCH] Do a sanity check on infile in lrzip to ensure it's working
 on a file it can compress.

---
 main.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/main.c b/main.c
index 33662d8..c2a6a7b 100644
--- a/main.c
+++ b/main.c
@@ -35,6 +35,12 @@
 #ifdef HAVE_SYS_RESOURCE_H
 # include <sys/resource.h>
 #endif
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif
 #include <math.h>
 #include <termios.h>
 #ifdef HAVE_ENDIAN_H
@@ -718,8 +724,19 @@ int main(int argc, char *argv[])
 			control.infile = argv[i];
 		else if (!(i == 0 && STDIN))
 			break;
-		if (control.infile && (strcmp(control.infile, "-") == 0))
-			control.flags |= FLAG_STDIN;
+		if (control.infile) {
+			if ((strcmp(control.infile, "-") == 0))
+				control.flags |= FLAG_STDIN;
+			else {
+				struct stat infile_stat;
+
+				stat(control.infile, &infile_stat);
+				if (unlikely(!S_ISREG(infile_stat.st_mode) &&
+					!S_ISLNK(infile_stat.st_mode)))
+						failure("lrzip only works directly on FILES.\n"
+						"Use lrztar or pipe through tar for compressing directories.\n");
+			}
+		}
 
 		if (INFO && STDIN)
 			failure("Will not get file info from STDIN\n");