From 089c9c701a1b68b721f479dfc0c58c35b9dd4175 Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Wed, 20 Jan 2016 04:39:53 +0000
Subject: [PATCH 1/4] implement libc specific _reopen_stream

musl defines stdin/stdio/stderr as constant types which means
we can not assign to them as we are doing here but works ok with glibc
therefore abstract out the _reopen_stream definition depending upon if
we are using glibc or otherwise

Origin:
http://git.alpinelinux.org/cgit/aports/tree/main/lvm2/fix-stdio-usage.patch

Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
Upstream-Status: Pending

 lib/commands/toolcontext.c | 22 +++++++++++-----------
 tools/lvmcmdline.c         |  6 +++---
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/lib/commands/toolcontext.c b/lib/commands/toolcontext.c
index a2f21b8..7f796e4 100644
--- a/lib/commands/toolcontext.c
+++ b/lib/commands/toolcontext.c
@@ -1637,7 +1637,10 @@ static void _init_globals(struct cmd_context *cmd)
 /*
  * Close and reopen stream on file descriptor fd.
  */
-static int _reopen_stream(FILE *stream, int fd, const char *mode, const char *name, FILE **new_stream)
+#ifdef __GLIBC__
+#define _reopen_stream(stream, fd, mode, name) __reopen_stream(stream, fd, mode, name, &stream)
+
+static int __reopen_stream(FILE *stream, int fd, const char *mode, const char *name, FILE **new_stream)
 {
 	int fd_copy, new_fd;
 
@@ -1664,6 +1667,9 @@ static int _reopen_stream(FILE *stream, int fd, const char *mode, const char *na
 
 	return 1;
 }
+#else
+#define _reopen_stream(stream, fd, mode, name) (freopen(NULL, mode, stream) != NULL)
+#endif
 
 static int _init_lvmetad(struct cmd_context *cmd)
 {
@@ -1741,7 +1747,6 @@ struct cmd_context *create_toolcontext(unsigned is_long_lived,
 				       unsigned set_filters)
 {
 	struct cmd_context *cmd;
-	FILE *new_stream;
 	int flags;
 
 #ifdef M_MMAP_MAX
@@ -1791,9 +1796,8 @@ struct cmd_context *create_toolcontext(unsigned is_long_lived,
 		if (is_valid_fd(STDIN_FILENO) &&
 		    ((flags = fcntl(STDIN_FILENO, F_GETFL)) > 0) &&
 		    (flags & O_ACCMODE) != O_WRONLY) {
-			if (!_reopen_stream(stdin, STDIN_FILENO, "r", "stdin", &new_stream))
+			if (!_reopen_stream(stdin, STDIN_FILENO, "r", "stdin"))
 				goto_out;
-			stdin = new_stream;
 			if (setvbuf(stdin, cmd->linebuffer, _IOLBF, linebuffer_size)) {
 				log_sys_error("setvbuf", "");
 				goto out;
@@ -1803,9 +1807,8 @@ struct cmd_context *create_toolcontext(unsigned is_long_lived,
 		if (is_valid_fd(STDOUT_FILENO) &&
 		    ((flags = fcntl(STDOUT_FILENO, F_GETFL)) > 0) &&
 		    (flags & O_ACCMODE) != O_RDONLY) {
-			if (!_reopen_stream(stdout, STDOUT_FILENO, "w", "stdout", &new_stream))
+			if (!_reopen_stream(stdout, STDOUT_FILENO, "w", "stdout"))
 				goto_out;
-			stdout = new_stream;
 			if (setvbuf(stdout, cmd->linebuffer + linebuffer_size,
 				     _IOLBF, linebuffer_size)) {
 				log_sys_error("setvbuf", "");
@@ -2131,7 +2134,6 @@ int refresh_toolcontext(struct cmd_context *cmd)
 void destroy_toolcontext(struct cmd_context *cmd)
 {
 	struct dm_config_tree *cft_cmdline;
-	FILE *new_stream;
 	int flags;
 
 	if (cmd->dump_filter && cmd->filter && cmd->filter->dump &&
@@ -2167,8 +2169,7 @@ void destroy_toolcontext(struct cmd_context *cmd)
 		if (is_valid_fd(STDIN_FILENO) &&
 		    ((flags = fcntl(STDIN_FILENO, F_GETFL)) > 0) &&
 		    (flags & O_ACCMODE) != O_WRONLY) {
-			if (_reopen_stream(stdin, STDIN_FILENO, "r", "stdin", &new_stream)) {
-				stdin = new_stream;
+			if (_reopen_stream(stdin, STDIN_FILENO, "r", "stdin")) {
 				setlinebuf(stdin);
 			} else
 				cmd->linebuffer = NULL;	/* Leave buffer in place (deliberate leak) */
@@ -2177,8 +2178,7 @@ void destroy_toolcontext(struct cmd_context *cmd)
 		if (is_valid_fd(STDOUT_FILENO) &&
 		    ((flags = fcntl(STDOUT_FILENO, F_GETFL)) > 0) &&
 		    (flags & O_ACCMODE) != O_RDONLY) {
-			if (_reopen_stream(stdout, STDOUT_FILENO, "w", "stdout", &new_stream)) {
-				stdout = new_stream;
+			if (_reopen_stream(stdout, STDOUT_FILENO, "w", "stdout")) {
 				setlinebuf(stdout);
 			} else
 				cmd->linebuffer = NULL;	/* Leave buffer in place (deliberate leak) */
diff --git a/tools/lvmcmdline.c b/tools/lvmcmdline.c
index 6577977..a33258a 100644
--- a/tools/lvmcmdline.c
+++ b/tools/lvmcmdline.c
@@ -1744,7 +1744,7 @@ static int _check_standard_fds(void)
 	int err = is_valid_fd(STDERR_FILENO);
 
 	if (!is_valid_fd(STDIN_FILENO) &&
-	    !(stdin = fopen(_PATH_DEVNULL, "r"))) {
+	    !freopen(_PATH_DEVNULL, "r", stdin)) {
 		if (err)
 			perror("stdin stream open");
 		else
@@ -1754,7 +1754,7 @@ static int _check_standard_fds(void)
 	}
 
 	if (!is_valid_fd(STDOUT_FILENO) &&
-	    !(stdout = fopen(_PATH_DEVNULL, "w"))) {
+	    !freopen(_PATH_DEVNULL, "w", stdout)) {
 		if (err)
 			perror("stdout stream open");
 		/* else no stdout */
@@ -1762,7 +1762,7 @@ static int _check_standard_fds(void)
 	}
 
 	if (!is_valid_fd(STDERR_FILENO) &&
-	    !(stderr = fopen(_PATH_DEVNULL, "w"))) {
+	    !freopen(_PATH_DEVNULL, "w", stderr)) {
 		printf("stderr stream open: %s\n",
 		       strerror(errno));
 		return 0;
-- 
2.7.0