awesome.spawn: Add a new argument for env

This adds a new argument to awesome.spawn that can be used to specify
the environment of the spawned process.

Signed-off-by: Uli Schlachter <psychon@znc.in>

spawn.c

@@ -475,6 +475,8 @@ child_exit_callback(GPid pid, gint status, gpointer user_data)
  * @tparam[opt=nil] function exit_callback Function to call on process exit. The
  * function arguments will be type of exit ("exit" or "signal") and the exit
  * code / the signal number causing process termination.
+ * @tparam[opt=nil] table cmd The environment to use for the spawned program.
+ * Without this, the spawned process inherits awesome's environment.
  * @treturn[1] integer Process ID if everything is OK.
  * @treturn[1] string Startup-notification ID, if `use_sn` is true.
  * @treturn[1] integer stdin, if `stdin` is true.
@@ -486,7 +488,7 @@ child_exit_callback(GPid pid, gint status, gpointer user_data)
 int
 luaA_spawn(lua_State *L)
 {
-    gchar **argv = NULL;
+    gchar **argv = NULL, **envp = NULL;
     bool use_sn = true, return_stdin = false, return_stdout = false, return_stderr = false;
     int stdin_fd = -1, stdout_fd = -1, stderr_fd = -1;
     int *stdin_ptr = NULL, *stdout_ptr = NULL, *stderr_ptr = NULL;
@@ -528,6 +530,17 @@ luaA_spawn(lua_State *L)
         return 1;
     }
 
+    if (!lua_isnoneornil(L, 7)) {
+        envp = parse_table_array(L, 7, &error);
+        if (error) {
+            g_strfreev(argv);
+            g_strfreev(envp);
+            lua_pushfstring(L, "spawn: environment parse error: %s", error->message);
+            g_error_free(error);
+            return 1;
+        }
+    }
+
     SnLauncherContext *context = NULL;
     if(use_sn)
     {
@@ -543,10 +556,11 @@ luaA_spawn(lua_State *L)
     }
 
     flags |= G_SPAWN_SEARCH_PATH | G_SPAWN_CLOEXEC_PIPES;
-    retval = g_spawn_async_with_pipes(NULL, argv, NULL, flags,
+    retval = g_spawn_async_with_pipes(NULL, argv, envp, flags,
                                       spawn_callback, context, &pid,
                                       stdin_ptr, stdout_ptr, stderr_ptr, &error);
     g_strfreev(argv);
+    g_strfreev(envp);
     if(!retval)
     {
         lua_pushstring(L, error->message);

tests/test-spawn.lua

@@ -71,6 +71,28 @@ local steps = {
                                      end
                                  })
 
+            -- Test that setting env vars works and that the env is cleared
+            local read_line = false
+            local pid, _, _, stdout = awesome.spawn({ "sh", "-c", "echo $AWESOME_SPAWN_TEST_VAR $HOME $USER" },
+                    false, false, true, false, nil, { "AWESOME_SPAWN_TEST_VAR=42" })
+            assert(type(pid) ~= "string", pid)
+            spawn.read_lines(require("lgi").Gio.UnixInputStream.new(stdout, true),
+                    function(line)
+                        assert(not read_line)
+                        read_line = true
+                        assert(line == "42", line)
+                        spawns_done = spawns_done + 1
+                    end, nil, true)
+
+            -- Test error in parse_table_array.
+            pid = awesome.spawn({"true"}, false, false, true, false, nil, { 0 })
+            assert(pid == 'spawn: environment parse error: Non-string argument at table index 1', pid)
+
+            -- Test error in parse_command.
+            pid = awesome.spawn({0}, false, false, true, false, nil, {})
+            assert(pid == 'spawn: parse error: Non-string argument at table index 1', pid)
+
+
             local steps_count = 0
             local err_count = 0
             spawn.with_line_callback({ "sh", "-c", "printf line1\\\\nline2\\\\nline3 ; echo err >&2 ; exit 42" }, {
@@ -98,7 +120,7 @@ local steps = {
                                      end
                                  })
         end
-        if spawns_done == 2 then
+        if spawns_done == 3 then
             assert(exit_yay == 0)
             assert(exit_snd == 42)
             assert(async_spawns_done == 2)