From 1e9cb8b8e19411b7ee093b51d3ce17402b9eea6c Mon Sep 17 00:00:00 2001
From: Phil Hord <phord@purestorage.com>
Date: Wed, 1 Feb 2017 10:21:48 -0800
Subject: [PATCH] dda->id is needed even when !LOOKAHEAD

In `ACCELERATION_RAMPING` code we use the dda->id field even when we do
not enable `LOOKAHEAD`. Expose the variable and its related `idcnt`
when `ACCELERATION_RAMPING` is used.

Add a regression-test to catch this in the future.
---
 Makefile-common                         | 3 +++
 dda.c                                   | 6 +++++-
 dda.h                                   | 2 +-
 testcases/config.regtest-no-lookahead.h | 7 +++++++
 4 files changed, 16 insertions(+), 2 deletions(-)
 create mode 100644 testcases/config.regtest-no-lookahead.h

diff --git a/Makefile-common b/Makefile-common
index d14b24b..a0a32f2 100644
--- a/Makefile-common
+++ b/Makefile-common
@@ -158,6 +158,9 @@ regressiontests:
 	# Config scenario: no endstops defined
 	$(MAKE) -f Makefile-AVR USER_CONFIG=testcases/config.regtest-no-endstops.h \
 	  MCU=atmega644 F_CPU=20000000UL EXTRA_CFLAGS=-Werror all
+	# Config scenario: ACCELERATION_RAMPING without LOOKAHEAD
+	$(MAKE) -f Makefile-AVR USER_CONFIG=testcases/config.regtest-no-lookahead.h \
+	  MCU=atmega644 F_CPU=20000000UL EXTRA_CFLAGS=-Werror all
 	# Don't forget the hostside simulator.
 	$(MAKE) -f Makefile-SIM USER_CONFIG=testcases/config.regtest-gen7-avr.h \
 	  MCU=atmega644 F_CPU=20000000UL EXTRA_CFLAGS=-Werror all
diff --git a/dda.c b/dda.c
index 8514e2e..7d58724 100644
--- a/dda.c
+++ b/dda.c
@@ -154,9 +154,11 @@ void dda_create(DDA *dda, const TARGET *target) {
   axes_int32_t steps;
 	uint32_t	distance, c_limit, c_limit_calc;
   enum axis_e i;
-  #ifdef LOOKAHEAD
+  #ifdef ACCELERATION_RAMPING
   // Number the moves to identify them; allowed to overflow.
   static uint8_t idcnt = 0;
+  #endif
+  #ifdef LOOKAHEAD
   static DDA* prev_dda = NULL;
 
   if (prev_dda && prev_dda->done)
@@ -184,6 +186,8 @@ void dda_create(DDA *dda, const TARGET *target) {
     dda->crossF = 0;
     dda->start_steps = 0;
     dda->end_steps = 0;
+  #endif
+  #ifdef ACCELERATION_RAMPING
     // Give this move an identifier.
     dda->id = idcnt++;
   #endif
diff --git a/dda.h b/dda.h
index 51ab484..2f07d91 100644
--- a/dda.h
+++ b/dda.h
@@ -134,11 +134,11 @@ typedef struct {
   // These two are based on the "fast" axis, the axis with the most steps.
   uint32_t          start_steps; ///< would be required to reach start feedrate
   uint32_t          end_steps; ///< would be required to stop from end feedrate
+  #endif
   // Number the moves to be able to test at the end of lookahead if the moves
   // are the same. Note: we do not need a lot of granularity here: more than
   // MOVEBUFFER_SIZE is already enough.
   uint8_t           id;
-  #endif
 	#endif
 	#ifdef ACCELERATION_TEMPORAL
   axes_uint32_t     step_interval;   ///< time between steps on each axis
diff --git a/testcases/config.regtest-no-lookahead.h b/testcases/config.regtest-no-lookahead.h
new file mode 100644
index 0000000..ed5322d
--- /dev/null
+++ b/testcases/config.regtest-no-lookahead.h
@@ -0,0 +1,7 @@
+
+// Configuration for controller board.
+#include "../config/board.gen7-v1.4.h"
+
+// Configuration for printer board.
+#include "../config/printer.wolfstrap.h"
+#undef LOOKAHEAD