use only the $PATH for exec'ing git commands

We need to correctly set up $PATH for non-c based git commands.
Since we already do this, we can just use that $PATH and execvp,
instead of looping over the paths with execve.

This patch adds a setup_path() function to exec_cmd.c, which sets
the $PATH order correctly for our search order. execv_git_cmd() is
stripped down to setting up argv and calling execvp(). git.c's
main() only only needs to call setup_path().

Signed-off-by: Scott R Parish <srp@srparish.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/exec_cmd.c b/exec_cmd.c
index 33b17a6b45699e73a9b58f0ff02135eae913b47d..2d0a75851284392aa8ae44bc486df6a034d0af13 100644 (file)
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -29,85 +29,69 @@ const char *git_exec_path(void)
        return builtin_exec_path;
 }
 
+static void add_path(struct strbuf *out, const char *path)
+{
+       if (path && *path) {
+               if (is_absolute_path(path))
+                       strbuf_addstr(out, path);
+               else
+                       strbuf_addstr(out, make_absolute_path(path));
+
+               strbuf_addch(out, ':');
+       }
+}
+
+void setup_path(const char *cmd_path)
+{
+       const char *old_path = getenv("PATH");
+       struct strbuf new_path;
+
+       strbuf_init(&new_path, 0);
+
+       add_path(&new_path, argv_exec_path);
+       add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
+       add_path(&new_path, builtin_exec_path);
+       add_path(&new_path, cmd_path);
+
+       if (old_path)
+               strbuf_addstr(&new_path, old_path);
+       else
+               strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
+
+       setenv("PATH", new_path.buf, 1);
+
+       strbuf_release(&new_path);
+}
 
 int execv_git_cmd(const char **argv)
 {
-       char git_command[PATH_MAX + 1];
-       int i;
-       const char *paths[] = { argv_exec_path,
-                               getenv(EXEC_PATH_ENVIRONMENT),
-                               builtin_exec_path };
-
-       for (i = 0; i < ARRAY_SIZE(paths); ++i) {
-               size_t len;
-               int rc;
-               const char *exec_dir = paths[i];
-               const char *tmp;
-
-               if (!exec_dir || !*exec_dir) continue;
-
-               if (*exec_dir != '/') {
-                       if (!getcwd(git_command, sizeof(git_command))) {
-                               fprintf(stderr, "git: cannot determine "
-                                       "current directory: %s\n",
-                                       strerror(errno));
-                               break;
-                       }
-                       len = strlen(git_command);
-
-                       /* Trivial cleanup */
-                       while (!prefixcmp(exec_dir, "./")) {
-                               exec_dir += 2;
-                               while (*exec_dir == '/')
-                                       exec_dir++;
-                       }
-
-                       rc = snprintf(git_command + len,
-                                     sizeof(git_command) - len, "/%s",
-                                     exec_dir);
-                       if (rc < 0 || rc >= sizeof(git_command) - len) {
-                               fprintf(stderr, "git: command name given "
-                                       "is too long.\n");
-                               break;
-                       }
-               } else {
-                       if (strlen(exec_dir) + 1 > sizeof(git_command)) {
-                               fprintf(stderr, "git: command name given "
-                                       "is too long.\n");
-                               break;
-                       }
-                       strcpy(git_command, exec_dir);
-               }
-
-               len = strlen(git_command);
-               rc = snprintf(git_command + len, sizeof(git_command) - len,
-                             "/git-%s", argv[0]);
-               if (rc < 0 || rc >= sizeof(git_command) - len) {
-                       fprintf(stderr,
-                               "git: command name given is too long.\n");
-                       break;
-               }
+       struct strbuf cmd;
+       const char *tmp;
 
-               /* argv[0] must be the git command, but the argv array
-                * belongs to the caller, and my be reused in
-                * subsequent loop iterations. Save argv[0] and
-                * restore it on error.
-                */
+       strbuf_init(&cmd, 0);
+       strbuf_addf(&cmd, "git-%s", argv[0]);
 
-               tmp = argv[0];
-               argv[0] = git_command;
+       /*
+        * argv[0] must be the git command, but the argv array
+        * belongs to the caller, and may be reused in
+        * subsequent loop iterations. Save argv[0] and
+        * restore it on error.
+        */
+       tmp = argv[0];
+       argv[0] = cmd.buf;
 
-               trace_argv_printf(argv, -1, "trace: exec:");
+       trace_argv_printf(argv, -1, "trace: exec:");
 
-               /* execve() can only ever return if it fails */
-               execve(git_command, (char **)argv, environ);
+       /* execvp() can only ever return if it fails */
+       execvp(cmd.buf, (char **)argv);
 
-               trace_printf("trace: exec failed: %s\n", strerror(errno));
+       trace_printf("trace: exec failed: %s\n", strerror(errno));
 
-               argv[0] = tmp;
-       }
-       return -1;
+       argv[0] = tmp;
 
+       strbuf_release(&cmd);
+
+       return -1;
 }
 
 

diff --git a/exec_cmd.h b/exec_cmd.h
index da99287552b5d3eafc495f998a936df81ee3f8b9..a892355c8212298130fb3925c6cba352ed6999b6 100644 (file)
--- a/exec_cmd.h
+++ b/exec_cmd.h
@@ -3,6 +3,7 @@
 
 extern void git_set_argv_exec_path(const char *exec_path);
 extern const char* git_exec_path(void);
+extern void setup_path(const char *);
 extern int execv_git_cmd(const char **argv); /* NULL terminated */
 extern int execl_git_cmd(const char *cmd, ...);
 

diff --git a/git.c b/git.c
index c7cabf5f348118f318d7c3abe55853b576869a98..4e10581101c26444da5c7c44a80219b11607705b 100644 (file)
--- a/git.c
+++ b/git.c
@@ -6,28 +6,6 @@
 const char git_usage_string[] =
        "git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate|--no-pager] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]";
 
-static void prepend_to_path(const char *dir, int len)
-{
-       const char *old_path = getenv("PATH");
-       char *path;
-       int path_len = len;
-
-       if (!old_path)
-               old_path = "/usr/local/bin:/usr/bin:/bin";
-
-       path_len = len + strlen(old_path) + 1;
-
-       path = xmalloc(path_len + 1);
-
-       memcpy(path, dir, len);
-       path[len] = ':';
-       memcpy(path + len + 1, old_path, path_len - len);
-
-       setenv("PATH", path, 1);
-
-       free(path);
-}
-
 static int handle_options(const char*** argv, int* argc, int* envchanged)
 {
        int handled = 0;
@@ -408,7 +386,7 @@ int main(int argc, const char **argv)
 {
        const char *cmd = argv[0] ? argv[0] : "git-help";
        char *slash = strrchr(cmd, '/');
-       const char *exec_path = NULL;
+       const char *cmd_path = NULL;
        int done_alias = 0;
 
        /*
@@ -418,10 +396,7 @@ int main(int argc, const char **argv)
         */
        if (slash) {
                *slash++ = 0;
-               if (*cmd == '/')
-                       exec_path = cmd;
-               else
-                       exec_path = xstrdup(make_absolute_path(cmd));
+               cmd_path = cmd;
                cmd = slash;
        }
 
@@ -458,16 +433,12 @@ int main(int argc, const char **argv)
        cmd = argv[0];
 
        /*
-        * We execute external git command via execv_git_cmd(),
-        * which looks at "--exec-path" option, GIT_EXEC_PATH
-        * environment, and $(gitexecdir) in Makefile while built,
-        * in this order.  For scripted commands, we prepend
-        * the value of the exec_path variable to the PATH.
+        * We use PATH to find git commands, but we prepend some higher
+        * precidence paths: the "--exec-path" option, the GIT_EXEC_PATH
+        * environment, and the $(gitexecdir) from the Makefile at build
+        * time.
         */
-       if (exec_path)
-               prepend_to_path(exec_path, strlen(exec_path));
-       exec_path = git_exec_path();
-       prepend_to_path(exec_path, strlen(exec_path));
+       setup_path(cmd_path);
 
        while (1) {
                /* See if it's an internal command */