# [PATCH 2/2] Handle invalid argc gently 7 messages from 2006-09-14 to 2006-09-14. Participants: Dmitry V. Levin, Junio C Hamano. Thread: https://gitlist.dev/t/5554 ## Dmitry V. Levin, 2006-09-14 01:04 Subject: [PATCH 2/2] Handle invalid argc gently Message-ID: <20060914010409.GB20593@nomad.office.altlinux.org> URL: https://gitlist.dev/e/20060914010409.GB20593%40nomad.office.altlinux.org ``` describe, git: Handle argc==0 case the same way as argc==1. merge-tree: Refuse excessive arguments. Signed-off-by: Dmitry V. Levin --- describe.c | 2 +- git.c | 2 +- merge-tree.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/describe.c b/describe.c index 5ed052d..2172e8f 100644 --- a/describe.c +++ b/describe.c @@ -163,7 +163,7 @@ int main(int argc, char **argv) setup_git_directory(); - if (i == argc) + if (i >= argc) describe("HEAD", 1); else while (i < argc) { diff --git a/git.c b/git.c index 47c85e1..8c182a5 100644 --- a/git.c +++ b/git.c @@ -294,7 +294,7 @@ static void handle_internal_command(int int main(int argc, const char **argv, char **envp) { - const char *cmd = argv[0]; + const char *cmd = argv[0] ? argv[0] : "git-help"; char *slash = strrchr(cmd, '/'); const char *exec_path = NULL; int done_alias = 0; diff --git a/merge-tree.c b/merge-tree.c index c154dcf..692ede0 100644 --- a/merge-tree.c +++ b/merge-tree.c @@ -337,7 +337,7 @@ int main(int argc, char **argv) struct tree_desc t[3]; void *buf1, *buf2, *buf3; - if (argc < 4) + if (argc != 4) usage(merge_tree_usage); setup_git_directory(); -- ldv ``` ## Junio C Hamano, 2006-09-14 01:12 Subject: Re: [PATCH 2/2] Handle invalid argc gently Message-ID: <7vu03b5k0t.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vu03b5k0t.fsf%40assigned-by-dhcp.cox.net In-Reply-To: <20060914010409.GB20593@nomad.office.altlinux.org> ``` "Dmitry V. Levin" writes: > describe, git: Handle argc==0 case the same way as argc==1. When does one get (ac == 0)? ``` ## Dmitry V. Levin, 2006-09-14 01:31 Subject: Re: [PATCH 2/2] Handle invalid argc gently Message-ID: <20060914013146.GD7044@basalt.office.altlinux.org> URL: https://gitlist.dev/e/20060914013146.GD7044%40basalt.office.altlinux.org In-Reply-To: <7vu03b5k0t.fsf@assigned-by-dhcp.cox.net> ``` On Wed, Sep 13, 2006 at 06:12:02PM -0700, Junio C Hamano wrote: > "Dmitry V. Levin" writes: > > > describe, git: Handle argc==0 case the same way as argc==1. > > When does one get (ac == 0)? When one executes something like execlp("git", NULL, NULL); -- ldv ``` ## Junio C Hamano, 2006-09-14 06:34 Subject: Re: [PATCH 2/2] Handle invalid argc gently Message-ID: <7vpsdz5542.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vpsdz5542.fsf%40assigned-by-dhcp.cox.net In-Reply-To: <20060914013146.GD7044@basalt.office.altlinux.org> ``` "Dmitry V. Levin" writes: > On Wed, Sep 13, 2006 at 06:12:02PM -0700, Junio C Hamano wrote: >> "Dmitry V. Levin" writes: >> >> > describe, git: Handle argc==0 case the same way as argc==1. >> >> When does one get (ac == 0)? > > When one executes something like > execlp("git", NULL, NULL); Fair enough. What is the valid reason to do execlp("git", NULL, NULL)? ``` ## Dmitry V. Levin, 2006-09-14 13:16 Subject: Re: [PATCH 2/2] Handle invalid argc gently Message-ID: <20060914131626.GE6709@basalt.office.altlinux.org> URL: https://gitlist.dev/e/20060914131626.GE6709%40basalt.office.altlinux.org In-Reply-To: <7vpsdz5542.fsf@assigned-by-dhcp.cox.net> ``` On Wed, Sep 13, 2006 at 11:34:05PM -0700, Junio C Hamano wrote: > "Dmitry V. Levin" writes: > > On Wed, Sep 13, 2006 at 06:12:02PM -0700, Junio C Hamano wrote: > >> "Dmitry V. Levin" writes: > >> > >> > describe, git: Handle argc==0 case the same way as argc==1. > >> > >> When does one get (ac == 0)? > > > > When one executes something like > > execlp("git", NULL, NULL); > > Fair enough. > > What is the valid reason to do execlp("git", NULL, NULL)? Personally I do not plan to execute git this way on regular basis, indeed. :) But argc == 0 is allowed, so why should git crash? -- ldv ``` ## Junio C Hamano, 2006-09-14 16:53 Subject: Re: [PATCH 2/2] Handle invalid argc gently Message-ID: <7virjq4cfj.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7virjq4cfj.fsf%40assigned-by-dhcp.cox.net In-Reply-To: <20060914131626.GE6709@basalt.office.altlinux.org> ``` "Dmitry V. Levin" writes: >> What is the valid reason to do execlp("git", NULL, NULL)? > > Personally I do not plan to execute git this way on regular basis, indeed. :) > > But argc == 0 is allowed, so why should git crash? Oh, no I was not arguing for making git crash. I was just trying to learn if there is a valid reason to choose to, or common misconfiguration that causes it to, run with ac == 0, since I did not think of any. It is good to be extra careful and defensive -- I just wanted to know if there is more to it. ``` ## Dmitry V. Levin, 2006-09-14 18:25 Subject: Re: [PATCH 2/2] Handle invalid argc gently Message-ID: <20060914182539.GA12109@basalt.office.altlinux.org> URL: https://gitlist.dev/e/20060914182539.GA12109%40basalt.office.altlinux.org In-Reply-To: <7virjq4cfj.fsf@assigned-by-dhcp.cox.net> ``` On Thu, Sep 14, 2006 at 09:53:36AM -0700, Junio C Hamano wrote: [...] > >> What is the valid reason to do execlp("git", NULL, NULL)? > > > > Personally I do not plan to execute git this way on regular basis, indeed. :) > > > > But argc == 0 is allowed, so why should git crash? > > Oh, no I was not arguing for making git crash. I was just > trying to learn if there is a valid reason to choose to, or > common misconfiguration that causes it to, run with ac == 0, > since I did not think of any. Well, the execlp example is somewhat dragged in. More common case is execvp: char *argv[] = { NULL }; execvp("git", argv); The argv array may be empty for various reasons, e.g. pointer arithmetic mistakes. -- ldv ```