Remove allowed shell check from swayrun

Because swayrun should be run from a safe environment, validating
the user's shell against /etc/shells seems unnecessary.

swayrun/main.c

@@ -1,48 +1,16 @@
-#define _POSIX_C_SOURCE 200809L // for getline
+#define _POSIX_C_SOURCE 200809L
 #include <errno.h>
-#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-#include "stringop.h"
 
 #define SWAY_COMMAND "sway"
 
-char allowed_shell(char *shell) {
-	FILE *fp;
-	char *line = NULL;
-	size_t len = 0;
-	char allowed = false;
-
-	if (strstr(shell, "false") != NULL || strstr(shell, "nologin") != NULL) {
-		return false;
-	}
-
-	fp = fopen("/etc/shells", "r");
-	if (fp == NULL) {
-		return true;
-	}
-
-	while (getline(&line, &len, fp) != -1) {
-		strip_whitespace(line);
-		if (strcmp(shell, line) == 0) {
-			allowed = true;
-			break;
-		}
-	}
-
-	fclose(fp);
-	if (line) {
-		free(line);
-	}
-	return allowed;
-}
-
 int main(int argc, char **argv) {
 	char *shell = getenv("SHELL");
 
-	if (shell && allowed_shell(shell)) {
+	if (shell) {
 		// 3 exec arguments + argc + argv[argc] NULL pointer
 		int exec_argc = 4 + argc;
 		char **exec_argv = malloc(exec_argc * sizeof(char*));

swayrun/meson.build

@@ -1,7 +1,5 @@
 executable(
   'swayrun',
   'main.c',
-  include_directories: [sway_inc],
-  link_with: [lib_sway_common],
   install: true
 )

swayrun/swayrun.1.scd

@@ -11,16 +11,11 @@ _swayrun_ [options...] [command]
 # DESCRIPTION
 
 Attempts to run *sway*(1) via the user's login shell. This allows environment
-configuration and other login actions, for example when run via a login manager.
+configuration and other login actions, for example when run via a display manager.
 
 All arguments to swayrun will be passed through unaltered to sway.
 
-If a valid login shell cannot be determined, sway will be executed normally.
-
-# CONFIGURATION
-
-swayrun will consult */etc/shells* if it exists for a list of valid login
-shells. In addition, *false* and *nologin* will be considered invalid shells.
+If a login shell cannot be determined, sway will be executed normally.
 
 # ENVIRONMENT
 
@@ -31,4 +26,4 @@ _SHELL_
 
 # SEE
 
-*sway*(1) *shells*(5)
+*sway*(1)