[Libguestfs] [PATCH v2] lib, lua: Fix usage of strerror_r

[Laszlo Ersek]

On 12/09/21 10:06, Richard W.M. Jones wrote:
>   $ ./run guestfish -vx add-drive foo "readonly:true"
>   libguestfs: trace: set_pgroup true
>   libguestfs: trace: set_pgroup = 0
>   libguestfs: trace: add_drive "foo" "readonly:true"
>   libguestfs: error: foo:
>   libguestfs: trace: add_drive = -1 (error)
>   libguestfs: trace: close
>   libguestfs: closing guestfs handle 0x55c0bacf12a0 (state 0)
> 
> Fix the usage of strerror_r by using the new wrapper defined in
> libguestfs-common.  A similar fix is made in the Lua bindings.
> 
> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2030396
> Reported-by: Masayoshi Mizuma <m.mizuma at jp.fujitsu.com>
> Tested-by: Masayoshi Mizuma <m.mizuma at jp.fujitsu.com>
> ---
>  common           |  2 +-
>  generator/lua.ml | 18 ++++++++----------
>  lib/errors.c     |  7 ++++---
>  3 files changed, 13 insertions(+), 14 deletions(-)
> 
> diff --git a/common b/common
> index a405dc599e..8fcdc2c6a1 160000
> --- a/common
> +++ b/common
> @@ -1 +1 @@
> -Subproject commit a405dc599e571410b83d145d02705708e1715e94
> +Subproject commit 8fcdc2c6a1e438012aaa24c58fa06f9d1efc6b93
> diff --git a/generator/lua.ml b/generator/lua.ml
> index 7b05c72e7a..0d7e63be0f 100644
> --- a/generator/lua.ml
> +++ b/generator/lua.ml
> @@ -164,10 +164,9 @@ guestfs_int_lua_create (lua_State *L)
>      return luaL_error (L, \"Guestfs.create: too many arguments\");
>  
>    g = guestfs_create_flags (flags);
> -  if (!g) {
> -    ignore_value (strerror_r (errno, err, sizeof err));
> -    return luaL_error (L, \"Guestfs.create: cannot create handle: %%s\", err);
> -  }
> +  if (!g)
> +    return luaL_error (L, \"Guestfs.create: cannot create handle: %%s\",
> +                       guestfs_int_strerror (errno, err, sizeof err));
>  
>    guestfs_set_error_handler (g, NULL, NULL);
>  
> @@ -243,10 +242,9 @@ error__tostring (lua_State *L)
>    lua_gettable (L, 1);
>    msg = luaL_checkstring (L, -1);
>  
> -  if (code) {
> -    ignore_value (strerror_r (code, err, sizeof err));
> -    lua_pushfstring (L, \"%%s: %%s\", msg, err);
> -  }
> +  if (code)
> +    lua_pushfstring (L, \"%%s: %%s\", msg,
> +                     guestfs_int_strerror (code, err, sizeof err));
>    else
>      lua_pushstring (L, msg);
>  
> @@ -655,8 +653,8 @@ get_string_list (lua_State *L, int index)
>  
>    strs = malloc ((len+1) * sizeof (char *));
>    if (strs == NULL) {
> -    ignore_value (strerror_r (errno, err, sizeof err));
> -    luaL_error (L, \"get_string_list: malloc failed: %%s\", err);
> +    luaL_error (L, \"get_string_list: malloc failed: %%s\",
> +                guestfs_int_strerror (errno, err, sizeof err));
>      /*NOTREACHED*/
>      return NULL;
>    }
> diff --git a/lib/errors.c b/lib/errors.c
> index bd9699eeb1..285209e44e 100644
> --- a/lib/errors.c
> +++ b/lib/errors.c
> @@ -322,6 +322,7 @@ guestfs_int_perrorf (guestfs_h *g, const char *fs, ...)
>    const int errnum = errno;
>    int err;
>    char buf[256];
> +  const char *errstr;
>    struct error_data *error_data = get_error_data (g);
>  
>    va_start (args, fs);
> @@ -330,11 +331,11 @@ guestfs_int_perrorf (guestfs_h *g, const char *fs, ...)
>  
>    if (err < 0) return;
>  
> -  ignore_value (strerror_r (errnum, buf, sizeof buf));
> +  errstr = guestfs_int_strerror (errnum, buf, sizeof buf);
>  
> -  msg = safe_realloc (g, msg, strlen (msg) + 2 + strlen (buf) + 1);
> +  msg = safe_realloc (g, msg, strlen (msg) + 2 + strlen (errstr) + 1);
>    strcat (msg, ": ");
> -  strcat (msg, buf);
> +  strcat (msg, errstr);
>  
>    /* set_last_error first so that the callback can access the error
>     * message and errno through the handle if it wishes.
> 

Reviewed-by: Laszlo Ersek <lersek at redhat.com>