Merge tag 'v1.9.1' into parse-bytecode

Fixes for stmhal USB mass storage, lwIP bindings and VFS regressions

This release provides an important fix for the USB mass storage device in
the stmhal port by implementing the SCSI SYNCHRONIZE_CACHE command, which
is now require by some Operating Systems.  There are also fixes for the
lwIP bindings to improve non-blocking sockets and error codes.  The VFS has
some regressions fixed including the ability to statvfs the root.

All changes are listed below.

py core:
- modbuiltins: add core-provided version of input() function
- objstr: catch case of negative "maxsplit" arg to str.rsplit()
- persistentcode: allow to compile with complex numbers disabled
- objstr: allow to compile with obj-repr D, and unicode disabled
- modsys: allow to compile with obj-repr D and PY_ATTRTUPLE disabled
- provide mp_decode_uint_skip() to help reduce stack usage
- makeqstrdefs.py: make script run correctly with Python 2.6
- objstringio: if created from immutable object, follow copy on write policy

extmod:
- modlwip: connect: for non-blocking mode, return EINPROGRESS
- modlwip: fix error codes for duplicate calls to connect()
- modlwip: accept: fix error code for non-blocking mode
- vfs: allow to statvfs the root directory
- vfs: allow "buffering" and "encoding" args to VFS's open()
- modframebuf: fix signed/unsigned comparison pendantic warning

lib:
- libm: use isfinite instead of finitef, for C99 compatibility
- utils/interrupt_char: remove support for KBD_EXCEPTION disabled

tests:
- basics/string_rsplit: add tests for negative "maxsplit" argument
- float: convert "sys.exit()" to "raise SystemExit"
- float/builtin_float_minmax: PEP8 fixes
- basics: convert "sys.exit()" to "raise SystemExit"
- convert remaining "sys.exit()" to "raise SystemExit"

unix port:
- convert to use core-provided version of built-in import()
- Makefile: replace references to make with $(MAKE)

windows port:
- convert to use core-provided version of built-in import()

qemu-arm port:
- Makefile: adjust object-file lists to get correct dependencies
- enable micropython.mem_*() functions to allow more tests

stmhal port:
- boards: enable DAC for NUCLEO_F767ZI board
- add support for NUCLEO_F446RE board
- pass USB handler as parameter to allow more than one USB handler
- usb: use local USB handler variable in Start-of-Frame handler
- usb: make state for USB device private to top-level USB driver
- usbdev: for MSC implement SCSI SYNCHRONIZE_CACHE command
- convert from using stmhal's input() to core provided version

cc3200 port:
- convert from using stmhal's input() to core provided version

teensy port:
- convert from using stmhal's input() to core provided version

esp8266 port:
- Makefile: replace references to make with $(MAKE)
- Makefile: add clean-modules target
- convert from using stmhal's input() to core provided version

zephyr port:
- modusocket: getaddrinfo: Fix mp_obj_len() usage
- define MICROPY_PY_SYS_PLATFORM (to "zephyr")
- machine_pin: use native Zephyr types for Zephyr API calls

docs:
- machine.Pin: remove out_value() method
- machine.Pin: add on() and off() methods
- esp8266: consistently replace Pin.high/low methods with .on/off
- esp8266/quickref: polish Pin.on()/off() examples
- network: move confusingly-named cc3200 Server class to its reference
- uos: deconditionalize, remove minor port-specific details
- uos: move cc3200 port legacy VFS mounting functions to its ref doc
- machine: sort machine classes in logical order, not alphabetically
- network: first step to describe standard network class interface

examples:
- embedding: use core-provided KeyboardInterrupt object

4 files changed, 39 insertions, 8 deletions

diff --git a/extmod/modframebuf.c b/extmod/modframebuf.c
index b8e84fe1c..a07392675 100644
--- a/extmod/modframebuf.c
+++ b/extmod/modframebuf.c
@@ -449,7 +449,7 @@ STATIC mp_obj_t framebuf_blit(size_t n_args, const mp_obj_t *args) {
         int cx1 = x1;
         for (int cx0 = x0; cx0 < x0end; ++cx0) {
             color = getpixel(source, cx1, y1);
-            if (color != key) {
+            if (color != (uint32_t)key) {
                 setpixel(self, cx0, y0, color);
             }
             ++cx1;
diff --git a/extmod/modlwip.c b/extmod/modlwip.c
index c72849cf9..01190d200 100644
--- a/extmod/modlwip.c
+++ b/extmod/modlwip.c
@@ -373,7 +373,7 @@ STATIC err_t _lwip_tcp_recv(void *arg, struct tcp_pcb *tcpb, struct pbuf *p, err
 }
 
 /*******************************************************************************/
-// Functions for socket send/recieve operations. Socket send/recv and friends call
+// Functions for socket send/receive operations. Socket send/recv and friends call
 // these to do the work.
 
 // Helper function for send/sendto to handle UDP packets.
@@ -732,7 +732,9 @@ STATIC mp_obj_t lwip_socket_accept(mp_obj_t self_in) {
 
     // accept incoming connection
     if (socket->incoming.connection == NULL) {
-        if (socket->timeout != -1) {
+        if (socket->timeout == 0) {
+            mp_raise_OSError(MP_EAGAIN);
+        } else if (socket->timeout != -1) {
             for (mp_uint_t retries = socket->timeout / 100; retries--;) {
                 mp_hal_delay_ms(100);
                 if (socket->incoming.connection != NULL) break;
@@ -800,12 +802,12 @@ STATIC mp_obj_t lwip_socket_connect(mp_obj_t self_in, mp_obj_t addr_in) {
         case MOD_NETWORK_SOCK_STREAM: {
             if (socket->state != STATE_NEW) {
                 if (socket->state == STATE_CONNECTED) {
-                    mp_raise_OSError(MP_EALREADY);
+                    mp_raise_OSError(MP_EISCONN);
                 } else {
-                    mp_raise_OSError(MP_EINPROGRESS);
+                    mp_raise_OSError(MP_EALREADY);
                 }
             }
-            // Register our recieve callback.
+            // Register our receive callback.
             tcp_recv(socket->pcb.tcp, _lwip_tcp_recv);
             socket->state = STATE_CONNECTING;
             err = tcp_connect(socket->pcb.tcp, &dest, port, _lwip_tcp_connected);
@@ -822,7 +824,7 @@ STATIC mp_obj_t lwip_socket_connect(mp_obj_t self_in, mp_obj_t addr_in) {
                     if (socket->state != STATE_CONNECTING) break;
                 }
                 if (socket->state == STATE_CONNECTING) {
-                    mp_raise_OSError(MP_ETIMEDOUT);
+                    mp_raise_OSError(MP_EINPROGRESS);
                 }
             } else {
                 while (socket->state == STATE_CONNECTING) {
diff --git a/extmod/modwebsocket.c b/extmod/modwebsocket.c
index 8200ea708..9e17d6a6d 100644
--- a/extmod/modwebsocket.c
+++ b/extmod/modwebsocket.c
@@ -132,7 +132,7 @@ STATIC mp_uint_t websocket_read(mp_obj_t self_in, void *buf, mp_uint_t size, int
 
                 self->buf_pos = 0;
                 self->to_recv = to_recv;
-                self->msg_sz = sz; // May be overriden by FRAME_OPT
+                self->msg_sz = sz; // May be overridden by FRAME_OPT
                 if (to_recv != 0) {
                     self->state = FRAME_OPT;
                 } else {
diff --git a/extmod/vfs.c b/extmod/vfs.c
index f158bd387..3bdce80db 100644
--- a/extmod/vfs.c
+++ b/extmod/vfs.c
@@ -228,11 +228,14 @@ mp_obj_t mp_vfs_umount(mp_obj_t mnt_in) {
 }
 MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_umount_obj, mp_vfs_umount);
 
+// Note: buffering and encoding args are currently ignored
 mp_obj_t mp_vfs_open(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     enum { ARG_file, ARG_mode, ARG_encoding };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_file, MP_ARG_OBJ | MP_ARG_REQUIRED, {.u_rom_obj = MP_ROM_PTR(&mp_const_none_obj)} },
         { MP_QSTR_mode, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_QSTR(MP_QSTR_r)} },
+        { MP_QSTR_buffering, MP_ARG_INT, {.u_int = -1} },
+        { MP_QSTR_encoding, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_PTR(&mp_const_none_obj)} },
     };
 
     // parse args
@@ -421,6 +424,32 @@ MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_stat_obj, mp_vfs_stat);
 mp_obj_t mp_vfs_statvfs(mp_obj_t path_in) {
     mp_obj_t path_out;
     mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out);
+    if (vfs == MP_VFS_ROOT) {
+        // statvfs called on the root directory, see if there's anything mounted there
+        for (vfs = MP_STATE_VM(vfs_mount_table); vfs != NULL; vfs = vfs->next) {
+            if (vfs->len == 1) {
+                break;
+            }
+        }
+
+        // If there's nothing mounted at root then return a mostly-empty tuple
+        if (vfs == NULL) {
+            mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(10, NULL));
+
+            // fill in: bsize, frsize, blocks, bfree, bavail, files, ffree, favail, flags
+            for (int i = 0; i <= 8; ++i) {
+                t->items[i] = MP_OBJ_NEW_SMALL_INT(0);
+            }
+
+            // Put something sensible in f_namemax
+            t->items[9] = MP_OBJ_NEW_SMALL_INT(MICROPY_ALLOC_PATH_MAX);
+
+            return MP_OBJ_FROM_PTR(t);
+        }
+
+        // VFS mounted at root so delegate the call to it
+        path_out = MP_OBJ_NEW_QSTR(MP_QSTR__slash_);
+    }
     return mp_vfs_proxy_call(vfs, MP_QSTR_statvfs, 1, &path_out);
 }
 MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_statvfs_obj, mp_vfs_statvfs);