Merge branch 'se/port_SUITE_env' into dev

* se/port_SUITE_env:
  fix open_port with many unset env vars
  allow open_port with env vars with trailing '=' on Windows

OTP-8701 se/port_SUITE_env

open_port/2 with the spawn and spawn_executable options can include an
{env,Env} option. In some cases unsetting variables would not work on Unix
(typically if more variables were unset than were actually present in the
environment).

1 files changed, 9 insertions, 1 deletions

diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c
index 151fa06e8e..737ffd9f94 100644
--- a/erts/emulator/sys/unix/sys.c
+++ b/erts/emulator/sys/unix/sys.c
@@ -1328,10 +1328,18 @@ static char **build_unix_environment(char *block)
 	}
     }
 
-    for (j = 0; j < i; j++) {
+    for (j = 0; j < i; ) {
         size_t last = strlen(cpp[j])-1;
 	if (cpp[j][last] == '=' && strchr(cpp[j], '=') == cpp[j]+last) {
 	    cpp[j] = cpp[--len];
+	    if (len < i) {
+		i--;
+	    } else {
+		j++;
+	    }
+	}
+	else {
+	    j++;
 	}
     }