Use /dev/null for update hook stdin.

Currently the update hook invoked by receive-pack has its stdin
connected to the pushing client.  The hook shouldn't attempt to
read from this stream, and doing so may consume data that was
meant for receive-pack.  Instead we should give the update hook
/dev/null as its stdin, ensuring that it always receives EOF and
doesn't disrupt the protocol if it attempts to read any data.

The post-update hook is similar, as it gets invoked with /dev/null
on stdin to prevent the hook from reading data from the client.
Previously we had invoked it with stdout also connected to /dev/null,
throwing away anything on stdout, to prevent client protocol errors.
Instead we should redirect stdout to stderr, like we do with the
update hook.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/receive-pack.c b/receive-pack.c
index 48e49465ba2b6e4b0640f054e0e2434e8060a7a3..c176d8fd008ad858a1e60e19e7bf3ea14d735eb5 100644 (file)
--- a/receive-pack.c
+++ b/receive-pack.c
@@ -73,7 +73,8 @@ static int run_update_hook(const char *refname,
 
        if (access(update_hook, X_OK) < 0)
                return 0;
-       code = run_command_opt(RUN_COMMAND_STDOUT_TO_STDERR,
+       code = run_command_opt(RUN_COMMAND_NO_STDIN
+               | RUN_COMMAND_STDOUT_TO_STDERR,
                update_hook, refname, old_hex, new_hex, NULL);
        switch (code) {
        case 0:
@@ -188,7 +189,8 @@ static void run_update_post_hook(struct command *cmd)
                argc++;
        }
        argv[argc] = NULL;
-       run_command_v_opt(argv, RUN_COMMAND_NO_STDIO);
+       run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
+               | RUN_COMMAND_STDOUT_TO_STDERR);
 }
 
 /*

diff --git a/run-command.c b/run-command.c
index 7e4ca43c626d4d60a2eeae79e0268e621931998c..cfbad74d145145944352c568064cc2f8c0d4c5cb 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -9,12 +9,12 @@ int run_command_v_opt(const char **argv, int flags)
        if (pid < 0)
                return -ERR_RUN_COMMAND_FORK;
        if (!pid) {
-               if (flags & RUN_COMMAND_NO_STDIO) {
+               if (flags & RUN_COMMAND_NO_STDIN) {
                        int fd = open("/dev/null", O_RDWR);
                        dup2(fd, 0);
-                       dup2(fd, 1);
                        close(fd);
-               } else if (flags & RUN_COMMAND_STDOUT_TO_STDERR)
+               }
+               if (flags & RUN_COMMAND_STDOUT_TO_STDERR)
                        dup2(2, 1);
                if (flags & RUN_GIT_CMD) {
                        execv_git_cmd(argv);

diff --git a/run-command.h b/run-command.h
index 8156eac31b25c07d97b8e2d0c54d4b49e10b0531..59c4476ced789441eea3f68bfc7377e7e15e9b14 100644 (file)
--- a/run-command.h
+++ b/run-command.h
@@ -11,7 +11,7 @@ enum {
        ERR_RUN_COMMAND_WAITPID_NOEXIT,
 };
 
-#define RUN_COMMAND_NO_STDIO 1
+#define RUN_COMMAND_NO_STDIN 1
 #define RUN_GIT_CMD         2  /*If this is to be git sub-command */
 #define RUN_COMMAND_STDOUT_TO_STDERR 4
 int run_command_v_opt(const char **argv, int opt);