connect: factor out "looks like command line option" check

We reject hostnames that start with a dash because they may be confused for command-line options. Let's factor out that notion into a helper function, as we'll use it in more places. And while it's simple now, it's not clear if some systems might need more complex logic to handle all cases. Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Jul 28, 2017 at 15:25 UTC 2491f77b90c2e5d47acbe7472c17e7de0af74f63
3 files changed +14 -1
cache.h
+8
@@ -991,6 +991,14 @@ char *strip_path_suffix(const char *path, const char *suffix);
991 int daemon_avoid_alias(const char *path);
992 extern int is_ntfs_dotgit(const char *name);
993
994 +/*
995 + * Returns true iff "str" could be confused as a command-line option when
996 + * passed to a sub-program like "ssh". Note that this has nothing to do with
997 + * shell-quoting, which should be handled separately; we're assuming here that
998 + * the string makes it verbatim to the sub-program.
999 + */
1000 +int looks_like_command_line_option(const char *str);
1001 +
1002 /**
1003 * Return a newly allocated string with the evaluation of
1004 * "$XDG_CONFIG_HOME/git/$filename" if $XDG_CONFIG_HOME is non-empty, otherwise
connect.c
+1 -1
@@ -754,7 +754,7 @@ struct child_process *git_connect(int fd[2], const char *url,
754 return NULL;
755 }
756
757 - if (ssh_host[0] == '-')
757 + if (looks_like_command_line_option(ssh_host))
758 die("strange hostname '%s' blocked", ssh_host);
759
760 ssh = getenv("GIT_SSH_COMMAND");
path.c
+5
@@ -1178,6 +1178,11 @@ int is_ntfs_dotgit(const char *name)
1178 }
1179 }
1180
1181 +int looks_like_command_line_option(const char *str)
1182 +{
1183 + return str && str[0] == '-';
1184 +}
1185 +
1186 char *xdg_config_home(const char *filename)
1187 {
1188 const char *home, *config_home;