From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Tue, 17 Mar 2026 09:08:42 +0000 (+0100)
Subject: cpio: Reduce visibility of variable buff
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df9ce5cd6cee61d07ac8665d59a2c1d7da38129b;p=thirdparty%2Flibarchive.git

cpio: Reduce visibility of variable buff

The buff variable is only used in entry_to_archive. Moving it into the
specific code block where it is actually used reduces its visibility and
thus makes it easier to read the code:

Since Windows indeed uses unsigned for read, this makes it much easier
to verify that buff never grows and cannot be too large.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
---

diff --git a/cpio/cpio.c b/cpio/cpio.c
index 0f170b107..9a6a558d1 100644
--- a/cpio/cpio.c
+++ b/cpio/cpio.c
@@ -115,7 +115,6 @@ static void	passphrase_free(char *);
 int
 main(int argc, char *argv[])
 {
-	static char buff[16384];
 	struct cpio _cpio; /* Allocated on stack. */
 	struct cpio *cpio;
 	struct cpio_owner owner;
@@ -126,9 +125,6 @@ main(int argc, char *argv[])
 
 	cpio = &_cpio;
 	memset(cpio, 0, sizeof(*cpio));
-	cpio->buff = buff;
-	cpio->buff_size = sizeof(buff);
-
 
 #if defined(HAVE_SIGACTION)
 	{
@@ -797,7 +793,6 @@ entry_to_archive(struct cpio *cpio, struct archive_entry *entry)
 	const char *destpath = archive_entry_pathname(entry);
 	const char *srcpath = archive_entry_sourcepath(entry);
 	int fd = -1;
-	ssize_t bytes_read;
 	int r;
 
 	/* Print out the destination name to the user. */
@@ -875,11 +870,14 @@ entry_to_archive(struct cpio *cpio, struct archive_entry *entry)
 		exit(1);
 
 	if (r >= ARCHIVE_WARN && archive_entry_size(entry) > 0 && fd >= 0) {
-		bytes_read = read(fd, cpio->buff, (unsigned)cpio->buff_size);
+		static char buff[16384];
+		ssize_t bytes_read;
+
+		bytes_read = read(fd, buff, sizeof(buff));
 		while (bytes_read > 0) {
 			ssize_t bytes_write;
 			bytes_write = archive_write_data(cpio->archive,
-			    cpio->buff, bytes_read);
+			    buff, bytes_read);
 			if (bytes_write < 0)
 				lafe_errc(1, archive_errno(cpio->archive),
 				    "%s", archive_error_string(cpio->archive));
@@ -888,8 +886,7 @@ entry_to_archive(struct cpio *cpio, struct archive_entry *entry)
 				    "Truncated write; file may have "
 				    "grown while being archived.");
 			}
-			bytes_read = read(fd, cpio->buff,
-			    (unsigned)cpio->buff_size);
+			bytes_read = read(fd, buff, sizeof(buff));
 		}
 	}
 
diff --git a/cpio/cpio.h b/cpio/cpio.h
index 9bc631b54..2621a4c3d 100644
--- a/cpio/cpio.h
+++ b/cpio/cpio.h
@@ -71,8 +71,6 @@ struct cpio {
 
 	/* Work data. */
 	struct archive   *matching;
-	char		 *buff;
-	size_t		  buff_size;
 	char		 *ppbuff;
 };