From e6060b9f36a75952dac2d3d1f9eedb264cb9622e Mon Sep 17 00:00:00 2001
From: Matt Woodward <46688854+woodfell@users.noreply.github.com>
Date: Tue, 21 Nov 2023 12:05:23 +1100
Subject: [PATCH] Fix decoding fixed length arrays of struct in python sbp2json
 [AP-946] (#1378)

# Description

@swift-nav/devinfra

Alter the python decoding generated code so that fixed length arrays
which contain structs (as opposed to primitive types) are properly
decoded with the correct parser for the filled type.

Variable length arrays are already decoded properly in all cases, it's
only fixed length arrays which are broken. Only the python binding are
affected by this bug.

# API compatibility

Sort of.

The output of the python version of `sbp2json` changes.

Currently messages which contain a fixed length array of structs are
decoded as byte arrays in the python version of sbp2json. This is
misleading.

The rust version of sbp2json is able to decode these constructs
properly. Therefore the output of the python and rust version of
`sbp2json` can differ given identical inputs.

In the current definition there are only 3 message types which suffer
from this behaviour - `MsgTrackingIq`, `MsgTrackingIqDepA`,
`MsgTrackingIqDepB` - all very rare and not really seen in the wild.

Therefore compatibility risk is practically zero.

## API compatibility plan

None required

# JIRA Reference

https://swift-nav.atlassian.net/browse/AP-946
---
 generator/sbpg/targets/python.py | 2 +-
 python/sbp/RELEASE-VERSION       | 2 +-
 python/sbp/tracking.py           | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/generator/sbpg/targets/python.py b/generator/sbpg/targets/python.py
index d9789bdd08..b48da0447f 100755
--- a/generator/sbpg/targets/python.py
+++ b/generator/sbpg/targets/python.py
@@ -72,7 +72,7 @@ def construct_format(f, type_map=CONSTRUCT_CODE):
     f_ = copy.copy(f)
     f_.type_id = fill
     s = f.options.get('size', None).value
-    return "'{id}' / construct.Array({size}, {type})".format(id=f.identifier, size=s, type=type_map.get(f_.type_id, 'construct.Byte'))
+    return "'{id}' / construct.Array({size}, {type})".format(id=f.identifier, size=s, type=type_map.get(f_.type_id, f'{fill}._parser'))
   elif f.type_id == 'array':
     fill = f.options['fill'].value
     if type_map.get(fill):
diff --git a/python/sbp/RELEASE-VERSION b/python/sbp/RELEASE-VERSION
index 26611488b0..50e2274e6d 100644
--- a/python/sbp/RELEASE-VERSION
+++ b/python/sbp/RELEASE-VERSION
@@ -1 +1 @@
-5.0.3
\ No newline at end of file
+5.0.3
diff --git a/python/sbp/tracking.py b/python/sbp/tracking.py
index a598600948..0f178cc61e 100644
--- a/python/sbp/tracking.py
+++ b/python/sbp/tracking.py
@@ -887,7 +887,7 @@ class MsgTrackingIq(SBP):
   _parser = construct.Struct(
                    'channel' / construct.Int8ul,
                    'sid' / GnssSignal._parser,
-                   'corrs' / construct.Array(3, construct.Byte),)
+                   'corrs' / construct.Array(3, TrackingChannelCorrelation._parser),)
   __slots__ = [
                'channel',
                'sid',
@@ -992,7 +992,7 @@ class MsgTrackingIqDepB(SBP):
   _parser = construct.Struct(
                    'channel' / construct.Int8ul,
                    'sid' / GnssSignal._parser,
-                   'corrs' / construct.Array(3, construct.Byte),)
+                   'corrs' / construct.Array(3, TrackingChannelCorrelationDep._parser),)
   __slots__ = [
                'channel',
                'sid',
@@ -1097,7 +1097,7 @@ class MsgTrackingIqDepA(SBP):
   _parser = construct.Struct(
                    'channel' / construct.Int8ul,
                    'sid' / GnssSignalDep._parser,
-                   'corrs' / construct.Array(3, construct.Byte),)
+                   'corrs' / construct.Array(3, TrackingChannelCorrelationDep._parser),)
   __slots__ = [
                'channel',
                'sid',