use execvpe if available in [exec]

On cygwin, setting environ before execvp() doesn't work,
but execvpe() does exist and works, so use that in preference

Signed-off-by: Steve Bennett <steveb@workware.net.au>

2 files changed, 6 insertions, 2 deletions

diff --git a/auto.def b/auto.def
index 55850e6..b52d047 100644
--- a/auto.def
+++ b/auto.def
@@ -79,7 +79,7 @@ if {[cc-check-function-in-lib socket socket]} {
     define-append LDLIBS [get-define lib_socket]
 }
 
-cc-check-functions ualarm lstat fork vfork system select
+cc-check-functions ualarm lstat fork vfork system select execvpe
 cc-check-functions backtrace geteuid mkstemp realpath strptime
 cc-check-functions regcomp waitpid sigaction sys_signame sys_siglist
 cc-check-functions syslog opendir readlink sleep usleep pipe getaddrinfo utimes
diff --git a/jim-exec.c b/jim-exec.c
index 6008490..7da97dc 100644
--- a/jim-exec.c
+++ b/jim-exec.c
@@ -139,6 +139,10 @@ int Jim_execInit(Jim_Interp *interp)
     #define JimDupFd dup
     #define JimFdOpenForRead(FD) fdopen((FD), "r")
     #define JimOpenForRead(NAME) open((NAME), O_RDONLY, 0)
+
+    #ifndef HAVE_EXECVPE
+        #define execvpe(ARG0, ARGV, ENV) execvp(ARG0, ARGV)
+    #endif
 #endif
 
 static const char *JimStrError(void);
@@ -983,7 +987,7 @@ badargs:
                 close(i);
             }
 
-            execvp(arg_array[firstArg], &arg_array[firstArg]);
+            execvpe(arg_array[firstArg], &arg_array[firstArg], Jim_GetEnviron());
 
             /* Need to prep an error message before vfork(), just in case */
             fprintf(stderr, "couldn't exec \"%s\"", arg_array[firstArg]);