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

6 files changed, 25 insertions, 9 deletions

diff --git a/tests/io/buffered_writer.py b/tests/io/buffered_writer.py
index bb7b4e8dba..c2cedb9912 100644
--- a/tests/io/buffered_writer.py
+++ b/tests/io/buffered_writer.py
@@ -4,9 +4,8 @@ try:
     io.BytesIO
     io.BufferedWriter
 except AttributeError:
-    import sys
     print('SKIP')
-    sys.exit()
+    raise SystemExit
 
 bts = io.BytesIO()
 buf = io.BufferedWriter(bts, 8)
diff --git a/tests/io/bytesio_cow.py b/tests/io/bytesio_cow.py
new file mode 100644
index 0000000000..92654a0003
--- /dev/null
+++ b/tests/io/bytesio_cow.py
@@ -0,0 +1,20 @@
+# Make sure that write operations on io.BytesIO don't
+# change original object it was constructed from.
+try:
+    import uio as io
+except ImportError:
+    import io
+
+b = b"foobar"
+
+a = io.BytesIO(b)
+a.write(b"1")
+print(b)
+print(a.getvalue())
+
+b = bytearray(b"foobar")
+
+a = io.BytesIO(b)
+a.write(b"1")
+print(b)
+print(a.getvalue())
diff --git a/tests/io/open_append.py b/tests/io/open_append.py
index 2120b72f04..a696823bc5 100644
--- a/tests/io/open_append.py
+++ b/tests/io/open_append.py
@@ -1,4 +1,3 @@
-import sys
 try:
     import uos as os
 except ImportError:
@@ -6,7 +5,7 @@ except ImportError:
 
 if not hasattr(os, "unlink"):
     print("SKIP")
-    sys.exit()
+    raise SystemExit
 
 # cleanup in case testfile exists
 try:
diff --git a/tests/io/open_plus.py b/tests/io/open_plus.py
index 98598ee672..bba96fa2f9 100644
--- a/tests/io/open_plus.py
+++ b/tests/io/open_plus.py
@@ -1,4 +1,3 @@
-import sys
 try:
     import uos as os
 except ImportError:
@@ -6,7 +5,7 @@ except ImportError:
 
 if not hasattr(os, "unlink"):
     print("SKIP")
-    sys.exit()
+    raise SystemExit
 
 # cleanup in case testfile exists
 try:
diff --git a/tests/io/resource_stream.py b/tests/io/resource_stream.py
index 86975f1181..37d985bf16 100644
--- a/tests/io/resource_stream.py
+++ b/tests/io/resource_stream.py
@@ -5,7 +5,7 @@ try:
     uio.resource_stream
 except AttributeError:
     print('SKIP')
-    sys.exit()
+    raise SystemExit
 
 buf = uio.resource_stream("data", "file2")
 print(buf.read())
diff --git a/tests/io/write_ext.py b/tests/io/write_ext.py
index 19b616174b..5a6eaa35cf 100644
--- a/tests/io/write_ext.py
+++ b/tests/io/write_ext.py
@@ -5,9 +5,8 @@ import uio
 try:
     uio.BytesIO
 except AttributeError:
-    import sys
     print('SKIP')
-    sys.exit()
+    raise SystemExit
 
 buf = uio.BytesIO()