Fix for bug #1276: Handle SHELL according to POSIX requirements.

POSIX requires that the value of SHELL in the makefile NOT be exported
to sub-commands.  Instead, the value in the environment when make was
invoked should be passed to the environment of sub-commands.  Note that
make still uses SHELL to _run_ sub-commands; it just doesn't change the
value of the SHELL variable in the environment of sub-commands.

As an extension to POSIX, if the makefile explicitly exports SHELL then
GNU make _will_ use it in the environment of sub-commands.

1 files changed, 2 insertions, 0 deletions

diff --git a/make.h b/make.h
index ad46e1f..55dcc21 100644
--- a/make.h
+++ b/make.h
@@ -496,6 +496,8 @@ extern int print_version_flag, print_directory_flag;
 extern int warn_undefined_variables_flag, posix_pedantic, not_parallel;
 extern int clock_skew_detected, rebuilding_makefiles;
 
+extern const char *env_shell;
+
 /* can we run commands via 'sh -c xxx' or must we use batch files? */
 extern int batch_mode_shell;