execute, pipe: pass environment variables

[Bruno Haible]

This changes execute() and create_pipe_*() so that they pass the environment
'environ' to child processes, like on Unix.

2008-09-29  Bruno Haible  <address@hidden>

        Propagate effects of putenv/setenv/unsetenv to child processes.
        * lib/execute.c (execute): Use spawnvpe instead of spawnvp.
        * lib/pipe.c (create_pipe): Likewise.

--- lib/execute.c.orig  2008-09-29 15:24:54.000000000 +0200
+++ lib/execute.c       2008-09-29 15:23:07.000000000 +0200
@@ -161,15 +161,23 @@
              && ((null_stdout && nulloutfd == STDOUT_FILENO)
                  || (null_stderr && nulloutfd == STDERR_FILENO)
                  || close (nulloutfd) >= 0))))
+    /* Use spawnvpe and pass the environment explicitly.  This is needed if
+       the program has modified the environment using putenv() or [un]setenv().
+       On Windows, programs have two environments, one in the "environment
+       block" of the process and managed through SetEnvironmentVariable(), and
+       one inside the process, in the location retrieved by the 'environ'
+       macro.  When using spawnvp() without 'e', the child process inherits a
+       copy of the environment block - ignoring the effects of putenv() and
+       [un]setenv().  */
     {
-      exitcode = spawnvp (P_WAIT, prog_path, prog_argv);
+      exitcode = spawnvpe (P_WAIT, prog_path, prog_argv, environ);
       if (exitcode < 0 && errno == ENOEXEC)
        {
          /* prog is not an native executable.  Try to execute it as a
             shell script.  Note that prepare_spawn() has already prepended
             a hidden element "sh.exe" to prog_argv.  */
          --prog_argv;
-         exitcode = spawnvp (P_WAIT, prog_argv[0], prog_argv);
+         exitcode = spawnvpe (P_WAIT, prog_argv[0], prog_argv, environ);
        }
     }
   if (nulloutfd >= 0)
--- lib/pipe.c.orig     2008-09-29 15:24:54.000000000 +0200
+++ lib/pipe.c  2008-09-29 15:22:51.000000000 +0200
@@ -202,15 +202,23 @@
        we want in the case of STD*_FILENO) and also orig_stdin,
        orig_stdout, orig_stderr (which is not explicitly wanted but
        harmless).  */
+    /* Use spawnvpe and pass the environment explicitly.  This is needed if
+       the program has modified the environment using putenv() or [un]setenv().
+       On Windows, programs have two environments, one in the "environment
+       block" of the process and managed through SetEnvironmentVariable(), and
+       one inside the process, in the location retrieved by the 'environ'
+       macro.  When using spawnvp() without 'e', the child process inherits a
+       copy of the environment block - ignoring the effects of putenv() and
+       [un]setenv().  */
     {
-      child = spawnvp (P_NOWAIT, prog_path, prog_argv);
+      child = spawnvpe (P_NOWAIT, prog_path, prog_argv, environ);
       if (child < 0 && errno == ENOEXEC)
        {
          /* prog is not an native executable.  Try to execute it as a
             shell script.  Note that prepare_spawn() has already prepended
             a hidden element "sh.exe" to prog_argv.  */
          --prog_argv;
-         child = spawnvp (P_NOWAIT, prog_argv[0], prog_argv);
+         child = spawnvpe (P_NOWAIT, prog_argv[0], prog_argv, environ);
        }
     }
   if (stdinfd >= 0)