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[PATCH 2/3] Redirect update hook stdout to stderr.

From
Shawn O. Pearce <spearce@spearce.org>
Date
Dec 31, 2006, 02:55 UTC
Message-ID
<20061231025519.GB5530@spearce.org>
In-Reply-To
<a0aecffe21074288c911c396f92901bfb558d591.1167533707.git.spearce@spearce.org>

If an update hook outputs to stdout then that output will be sent back over the wire to the push client as though it were part of the git protocol. This tends to cause protocol errors on the client end of the connection, as the hook output is not expected in that context. Most hook developers work around this by making sure their hook outputs everything to stderr.

But hooks shouldn't need to perform such special behavior. Instead we can just dup stderr to stdout prior to invoking the update hook.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 receive-pack.c |    3 ++-
 run-command.c  |   32 ++++++++++++++++++++++++++------
 run-command.h  |    2 ++
 3 files changed, 30 insertions(+), 7 deletions(-)
diff --git a/receive-pack.c b/receive-pack.c
index af05a61..64289e9 100644
--- 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(update_hook, refname, old_hex, new_hex, NULL);
+	code = run_command_opt(RUN_COMMAND_STDOUT_TO_STDERR,
+		update_hook, refname, old_hex, new_hex, NULL);
 	switch (code) {
 	case 0:
 		return 0;
diff --git a/run-command.c b/run-command.c
index d0330c3..7e4ca43 100644
--- a/run-command.c
+++ b/run-command.c
@@ -14,7 +14,8 @@ int run_command_v_opt(const char **argv, int flags)
 			dup2(fd, 0);
 			dup2(fd, 1);
 			close(fd);
-		}
+		} else if (flags & RUN_COMMAND_STDOUT_TO_STDERR)
+			dup2(2, 1);
 		if (flags & RUN_GIT_CMD) {
 			execv_git_cmd(argv);
 		} else {
@@ -51,14 +52,12 @@ int run_command_v(const char **argv)
 	return run_command_v_opt(argv, 0);
 }
 
-int run_command(const char *cmd, ...)
+static int run_command_va_opt(int opt, const char *cmd, va_list param)
 {
 	int argc;
 	const char *argv[MAX_RUN_COMMAND_ARGS];
 	const char *arg;
-	va_list param;
 
-	va_start(param, cmd);
 	argv[0] = (char*) cmd;
 	argc = 1;
 	while (argc < MAX_RUN_COMMAND_ARGS) {
@@ -66,8 +65,29 @@ int run_command(const char *cmd, ...)
 		if (!arg)
 			break;
 	}
-	va_end(param);
 	if (MAX_RUN_COMMAND_ARGS <= argc)
 		return error("too many args to run %s", cmd);
-	return run_command_v_opt(argv, 0);
+	return run_command_v_opt(argv, opt);
+}
+
+int run_command_opt(int opt, const char *cmd, ...)
+{
+	va_list params;
+	int r;
+
+	va_start(params, cmd);
+	r = run_command_va_opt(opt, cmd, params);
+	va_end(params);
+	return r;
+}
+
+int run_command(const char *cmd, ...)
+{
+	va_list params;
+	int r;
+
+	va_start(params, cmd);
+	r = run_command_va_opt(0, cmd, params);
+	va_end(params);
+	return r;
 }
diff --git a/run-command.h b/run-command.h
index 82a0861..8156eac 100644
--- a/run-command.h
+++ b/run-command.h
@@ -13,8 +13,10 @@ enum {
 
 #define RUN_COMMAND_NO_STDIO 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);
 int run_command_v(const char **argv);
+int run_command_opt(int opt, const char *cmd, ...);
 int run_command(const char *cmd, ...);
 
 #endif
-- 
1.5.0.rc0.g6bb1
Next: Shawn O. Pearce
Message 1 of 3 in “Redirect update hook stdout to stderr.”
  1. 2/3 Redirect update hook stdout to stderr.Shawn O. Pearce, Dec 31, 2006
  2. 3/3 Use /dev/null for update hook stdin.Shawn O. Pearce, Dec 31, 2006
  3. Junio C HamanoDec 31, 2006

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