[PATCH 3/6] git_connect: use argv_array
This avoids magic numbers when we allocate fixed-size argv arrays, and makes it more obvious that we are not overflowing.
It is also the first step to fixing a memory leak. When git_connect returns a child_process struct, the argv array in the struct is dynamically allocated, but the individual strings are not (they are either owned elsewhere, or are freed). Later, in finish_connect, we free the array but leave the strings alone.
This works for the child_process created by git_connect, but if we use transport_take_over, we may also end up with a child_process created by transport-helper's get_helper. In that case, the strings are freshly allocated, and we would want to free them. However, we have no idea in finish_connect which type we have.
By consistently using run-command's internal argv-array, we do not have to worry about this issue at all; finish_command takes care of it for us, and we can drop our manual free entirely.
Note that this actually makes the get_helper leak slightly worse; now we are leaking both the strings and the array. But when we adjust it in a future patch, that leak will go away entirely.
Signed-off-by: Jeff King <peff@peff.net>
---
connect.c | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)
Show changes to connect.c +10 −18
diff --git a/connect.c b/connect.c
index a983d06..94a6650 100644
--- a/connect.c
+++ b/connect.c
@@ -534,22 +534,18 @@ static int git_use_proxy(const char *host)
static struct child_process *git_proxy_connect(int fd[2], char *host)
{
const char *port = STR(DEFAULT_GIT_PORT);
- const char **argv;
struct child_process *proxy;
get_host_and_port(&host, &port);
- argv = xmalloc(sizeof(*argv) * 4);
- argv[0] = git_proxy_command;
- argv[1] = host;
- argv[2] = port;
- argv[3] = NULL;
proxy = xcalloc(1, sizeof(*proxy));
- proxy->argv = argv;
+ argv_array_push(&proxy->args, git_proxy_command);
+ argv_array_push(&proxy->args, host);
+ argv_array_push(&proxy->args, port);
proxy->in = -1;
proxy->out = -1;
if (start_command(proxy))
- die("cannot start proxy %s", argv[0]);
+ die("cannot start proxy %s", git_proxy_command);
fd[0] = proxy->out; /* read from proxy stdout */
fd[1] = proxy->in; /* write to proxy stdin */
return proxy;
@@ -663,7 +659,6 @@ struct child_process *git_connect(int fd[2], const char *url,
char *hostandport, *path;
struct child_process *conn = &no_fork;
enum protocol protocol;
- const char **arg;
struct strbuf cmd = STRBUF_INIT;
/* Without this we cannot rely on waitpid() to tell
@@ -707,7 +702,6 @@ struct child_process *git_connect(int fd[2], const char *url,
sq_quote_buf(&cmd, path);
conn->in = conn->out = -1;
- conn->argv = arg = xcalloc(7, sizeof(*arg));
if (protocol == PROTO_SSH) {
const char *ssh = getenv("GIT_SSH");
int putty = ssh && strcasestr(ssh, "plink");
@@ -718,22 +712,21 @@ struct child_process *git_connect(int fd[2], const char *url,
if (!ssh) ssh = "ssh";
- *arg++ = ssh;
+ argv_array_push(&conn->args, ssh);
if (putty && !strcasestr(ssh, "tortoiseplink"))
- *arg++ = "-batch";
+ argv_array_push(&conn->args, "-batch");
if (port) {
/* P is for PuTTY, p is for OpenSSH */
- *arg++ = putty ? "-P" : "-p";
- *arg++ = port;
+ argv_array_push(&conn->args, putty ? "-P" : "-p");
+ argv_array_push(&conn->args, port);
}
- *arg++ = ssh_host;
+ argv_array_push(&conn->args, ssh_host);
} else {
/* remove repo-local variables from the environment */
conn->env = local_repo_env;
conn->use_shell = 1;
}
- *arg++ = cmd.buf;
- *arg = NULL;
+ argv_array_push(&conn->args, cmd.buf);
if (start_command(conn))
die("unable to fork");
@@ -759,7 +752,6 @@ int finish_connect(struct child_process *conn)
return 0;
code = finish_command(conn);
- free(conn->argv);
free(conn);
return code;
}
--
2.0.0.rc1.436.g03cb729
Jeff King