From: Tim Kientzle <kientzle@acm.org>
Date: Sat, 19 Mar 2016 18:18:16 +0000 (-0700)
Subject: Comment fileno() usage
X-Git-Tag: v3.1.901a~9^2~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4f8e09322f156cb7880759d49a9bcc3fed9a5b95;p=thirdparty%2Flibarchive.git

Comment fileno() usage
---

diff --git a/libarchive/archive_read_open_file.c b/libarchive/archive_read_open_file.c
index 3b7ff5ffd..bfe933bf3 100644
--- a/libarchive/archive_read_open_file.c
+++ b/libarchive/archive_read_open_file.c
@@ -83,8 +83,9 @@ archive_read_open_FILE(struct archive *a, FILE *f)
 	mine->f = f;
 	/*
 	 * If we can't fstat() the file, it may just be that it's not
-	 * a file.  (FILE * objects can wrap many kinds of I/O
-	 * streams, some of which don't support fileno()).)
+	 * a file.  (On some platforms, FILE * objects can wrap I/O
+	 * streams that don't support fileno()).  As a result, fileno()
+	 * should be used cautiously.)
 	 */
 	if (fstat(fileno(mine->f), &st) == 0 && S_ISREG(st.st_mode)) {
 		archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
@@ -151,6 +152,7 @@ file_skip(struct archive *a, void *client_data, int64_t request)
 	}
 
 #ifdef __ANDROID__
+        /* fileno() isn't safe on all platforms ... see above. */
 	if (lseek(fileno(mine->f), skip, SEEK_CUR) < 0)
 #elif HAVE_FSEEKO
 	if (fseeko(mine->f, skip, SEEK_CUR) != 0)