Merge branch 'jk/run-command-eacces' into maint

When PATH contains an unreadable directory, alias expansion code did
not kick in, and failed with an error that said "git-subcmd" was not
found.

By Jeff King (1) and Ramsay Jones (1)
* jk/run-command-eacces:
run-command: treat inaccessible directories as ENOENT
compat/mingw.[ch]: Change return type of exec functions to int

diff --git a/cache.h b/cache.h
index 806bf2b76fbbf7b30b70bad65220d5255a67c69e..5e6eef9b4d0fca96fb0f90265f5f68d640f1583a 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -1305,4 +1305,6 @@ extern struct startup_info *startup_info;
 /* builtin/merge.c */
 int checkout_fast_forward(const unsigned char *from, const unsigned char *to);
 
+int sane_execvp(const char *file, char *const argv[]);
+
 #endif /* CACHE_H */

diff --git a/compat/mingw.c b/compat/mingw.c
index a0ac487c0c12ea0e7c81485b5784e28f2115a2ea..afc892d6b1837d807490f42790bf29686d074a10 100644 (file)
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1003,7 +1003,7 @@ static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
        }
 }
 
-void mingw_execvp(const char *cmd, char *const *argv)
+int mingw_execvp(const char *cmd, char *const *argv)
 {
        char **path = get_path_split();
        char *prog = path_lookup(cmd, path, 0);
@@ -1015,11 +1015,13 @@ void mingw_execvp(const char *cmd, char *const *argv)
                errno = ENOENT;
 
        free_path_split(path);
+       return -1;
 }
 
-void mingw_execv(const char *cmd, char *const *argv)
+int mingw_execv(const char *cmd, char *const *argv)
 {
        mingw_execve(cmd, argv, environ);
+       return -1;
 }
 
 int mingw_kill(pid_t pid, int sig)

diff --git a/compat/mingw.h b/compat/mingw.h
index 0ff1e04812ef2491f15b1d40bb8e1c2977b26d98..ef5b15014e98b2e4d20a8087dd497216db95d2fc 100644 (file)
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -274,9 +274,9 @@ int mingw_utime(const char *file_name, const struct utimbuf *times);
 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env,
                     const char *dir,
                     int fhin, int fhout, int fherr);
-void mingw_execvp(const char *cmd, char *const *argv);
+int mingw_execvp(const char *cmd, char *const *argv);
 #define execvp mingw_execvp
-void mingw_execv(const char *cmd, char *const *argv);
+int mingw_execv(const char *cmd, char *const *argv);
 #define execv mingw_execv
 
 static inline unsigned int git_ntohl(unsigned int x)

diff --git a/exec_cmd.c b/exec_cmd.c
index 171e841531de7fd5b51aa26f639104382395b854..125fa6fabf503d29cb82b2ccbc92359abf95b0e8 100644 (file)
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -134,7 +134,7 @@ int execv_git_cmd(const char **argv) {
        trace_argv_printf(nargv, "trace: exec:");
 
        /* execvp() can only ever return if it fails */
-       execvp("git", (char **)nargv);
+       sane_execvp("git", (char **)nargv);
 
        trace_printf("trace: exec failed: %s\n", strerror(errno));
 

diff --git a/run-command.c b/run-command.c
index 1db8abf9843516576f30f8105bbfdd66487db6e1..9c5a564ece033e8584be14c640f6a9995ecd1cff 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -76,6 +76,68 @@ static inline void dup_devnull(int to)
 }
 #endif
 
+static char *locate_in_PATH(const char *file)
+{
+       const char *p = getenv("PATH");
+       struct strbuf buf = STRBUF_INIT;
+
+       if (!p || !*p)
+               return NULL;
+
+       while (1) {
+               const char *end = strchrnul(p, ':');
+
+               strbuf_reset(&buf);
+
+               /* POSIX specifies an empty entry as the current directory. */
+               if (end != p) {
+                       strbuf_add(&buf, p, end - p);
+                       strbuf_addch(&buf, '/');
+               }
+               strbuf_addstr(&buf, file);
+
+               if (!access(buf.buf, F_OK))
+                       return strbuf_detach(&buf, NULL);
+
+               if (!*end)
+                       break;
+               p = end + 1;
+       }
+
+       strbuf_release(&buf);
+       return NULL;
+}
+
+static int exists_in_PATH(const char *file)
+{
+       char *r = locate_in_PATH(file);
+       free(r);
+       return r != NULL;
+}
+
+int sane_execvp(const char *file, char * const argv[])
+{
+       if (!execvp(file, argv))
+               return 0; /* cannot happen ;-) */
+
+       /*
+        * When a command can't be found because one of the directories
+        * listed in $PATH is unsearchable, execvp reports EACCES, but
+        * careful usability testing (read: analysis of occasional bug
+        * reports) reveals that "No such file or directory" is more
+        * intuitive.
+        *
+        * We avoid commands with "/", because execvp will not do $PATH
+        * lookups in that case.
+        *
+        * The reassignment of EACCES to errno looks like a no-op below,
+        * but we need to protect against exists_in_PATH overwriting errno.
+        */
+       if (errno == EACCES && !strchr(file, '/'))
+               errno = exists_in_PATH(file) ? EACCES : ENOENT;
+       return -1;
+}
+
 static const char **prepare_shell_cmd(const char **argv)
 {
        int argc, nargc = 0;
@@ -114,7 +176,7 @@ static int execv_shell_cmd(const char **argv)
 {
        const char **nargv = prepare_shell_cmd(argv);
        trace_argv_printf(nargv, "trace: exec:");
-       execvp(nargv[0], (char **)nargv);
+       sane_execvp(nargv[0], (char **)nargv);
        free(nargv);
        return -1;
 }
@@ -339,7 +401,7 @@ int start_command(struct child_process *cmd)
                } else if (cmd->use_shell) {
                        execv_shell_cmd(cmd->argv);
                } else {
-                       execvp(cmd->argv[0], (char *const*) cmd->argv);
+                       sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
                }
                if (errno == ENOENT) {
                        if (!cmd->silent_exec_failure)

diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index 8d4938f019ca406c0f248d19d046356dff1ac09a..17e969df609f71b0b4562cff8fda112632d27442 100755 (executable)
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -34,4 +34,17 @@ test_expect_success POSIXPERM 'run_command reports EACCES' '
        grep "fatal: cannot exec.*hello.sh" err
 '
 
+test_expect_success POSIXPERM 'unreadable directory in PATH' '
+       mkdir local-command &&
+       test_when_finished "chmod u+rwx local-command && rm -fr local-command" &&
+       git config alias.nitfol "!echo frotz" &&
+       chmod a-rx local-command &&
+       (
+               PATH=./local-command:$PATH &&
+               git nitfol >actual
+       ) &&
+       echo frotz >expect &&
+       test_cmp expect actual
+'
+
 test_done