1 files changed, 30 insertions, 23 deletions

diff --git a/src/callproc.c b/src/callproc.c
index e8b61b9f01f..0636571b26c 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -466,7 +466,7 @@ call_process (ptrdiff_t nargs, Lisp_Object *args, int filefd,
       && SREF (path, 1) == ':')
     path = Fsubstring (path, make_number (2), Qnil);
 
-  new_argv = SAFE_ALLOCA ((nargs > 4 ? nargs - 2 : 2) * sizeof *new_argv);
+  SAFE_NALLOCA (new_argv, 1, nargs < 4 ? 2 : nargs - 2);
 
   {
     struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
@@ -1151,6 +1151,25 @@ add_env (char **env, char **new_env, char *string)
   return new_env;
 }
 
+#ifndef DOS_NT
+
+/* 'exec' failed inside a child running NAME, with error number ERR.
+   Report the error and exit the child.  */
+
+static _Noreturn void
+exec_failed (char const *name, int err)
+{
+  /* Avoid deadlock if the child's perror writes to a full pipe; the
+     pipe's reader is the parent, but with vfork the parent can't
+     run until the child exits.  Truncate the diagnostic instead.  */
+  fcntl (STDERR_FILENO, F_SETFL, O_NONBLOCK);
+
+  errno = err;
+  emacs_perror (name);
+  _exit (err == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
+}
+#endif
+
 /* This is the last thing run in a newly forked inferior
    either synchronous or asynchronous.
    Copy descriptors IN, OUT and ERR as descriptors 0, 1 and 2.
@@ -1174,8 +1193,6 @@ child_setup (int in, int out, int err, char **new_argv, bool set_pgrp,
   int cpid;
   HANDLE handles[3];
 #else
-  int exec_errno;
-
   pid_t pid = getpid ();
 #endif /* WINDOWSNT */
 
@@ -1196,6 +1213,8 @@ child_setup (int in, int out, int err, char **new_argv, bool set_pgrp,
        on that.  */
     pwd_var = xmalloc (i + 5);
 #else
+    if (MAX_ALLOCA - 5 < i)
+      exec_failed (new_argv[0], ENOMEM);
     pwd_var = alloca (i + 5);
 #endif
     temp = pwd_var + 4;
@@ -1262,6 +1281,8 @@ child_setup (int in, int out, int err, char **new_argv, bool set_pgrp,
       }
 
     /* new_length + 2 to include PWD and terminating 0.  */
+    if (MAX_ALLOCA / sizeof *env - 2 < new_length)
+      exec_failed (new_argv[0], ENOMEM);
     env = new_env = alloca ((new_length + 2) * sizeof *env);
     /* If we have a PWD envvar, pass one down,
        but with corrected value.  */
@@ -1270,6 +1291,8 @@ child_setup (int in, int out, int err, char **new_argv, bool set_pgrp,
 
     if (STRINGP (display))
       {
+        if (MAX_ALLOCA - sizeof "DISPLAY=" < SBYTES (display))
+          exec_failed (new_argv[0], ENOMEM);
         char *vdata = alloca (sizeof "DISPLAY=" + SBYTES (display));
         strcpy (vdata, "DISPLAY=");
         strcat (vdata, SSDATA (display));
@@ -1345,16 +1368,7 @@ child_setup (int in, int out, int err, char **new_argv, bool set_pgrp,
   tcsetpgrp (0, pid);
 
   execve (new_argv[0], new_argv, env);
-  exec_errno = errno;
-
-  /* Avoid deadlock if the child's perror writes to a full pipe; the
-     pipe's reader is the parent, but with vfork the parent can't
-     run until the child exits.  Truncate the diagnostic instead.  */
-  fcntl (STDERR_FILENO, F_SETFL, O_NONBLOCK);
-
-  errno = exec_errno;
-  emacs_perror (new_argv[0]);
-  _exit (exec_errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
+  exec_failed (new_argv[0], errno);
 
 #else /* MSDOS */
   pid = run_msdos_command (new_argv, pwd_var + 4, in, out, err, env);
@@ -1543,20 +1557,13 @@ init_callproc_1 (void)
 void
 init_callproc (void)
 {
-  char *data_dir = egetenv ("EMACSDATA");
+  bool data_dir = egetenv ("EMACSDATA") != 0;
 
-  register char * sh;
+  char *sh;
   Lisp_Object tempdir;
 #ifdef HAVE_NS
   if (data_dir == 0)
-    {
-      const char *etc_dir = ns_etc_directory ();
-      if (etc_dir)
-        {
-          data_dir = alloca (strlen (etc_dir) + 1);
-          strcpy (data_dir, etc_dir);
-        }
-    }
+    data_dir == ns_etc_directory () != 0;
 #endif
 
   if (!NILP (Vinstallation_directory))