From 5a0d99a40af2c0c64a9529da0c29f10c7f3a38fc Mon Sep 17 00:00:00 2001
From: Alden Hart <alden08@harts.org>
Date: Sat, 24 Dec 2016 10:03:19 -0500
Subject: [PATCH] Fixed $$ lockup problem. Root cause was mis-handling of stale
 NV lists.

---
 g2core/config_app.cpp  |  8 ++++----
 g2core/error.h         |  2 +-
 g2core/g2core.cppproj  | 12 ++++++------
 g2core/json_parser.cpp |  7 +++++--
 4 files changed, 16 insertions(+), 13 deletions(-)
 mode change 100755 => 100644 g2core/json_parser.cpp

diff --git a/g2core/config_app.cpp b/g2core/config_app.cpp
index 9ddff796..6ff570b0 100644
--- a/g2core/config_app.cpp
+++ b/g2core/config_app.cpp
@@ -1117,7 +1117,7 @@ static stat_t _do_outputs(nvObj_t *nv)  // print parameters for all output group
     }
     return (STAT_COMPLETE);
 }
-/*
+
 static stat_t _do_heaters(nvObj_t *nv)  // print parameters for all heater groups
 {
     char group[GROUP_LEN];
@@ -1127,7 +1127,7 @@ static stat_t _do_heaters(nvObj_t *nv)  // print parameters for all heater group
     }
     return (STAT_COMPLETE);
 }
-*/
+
 static stat_t _do_all(nvObj_t *nv)  // print all parameters
 {
     _do_group(nv, (char *)"sys");   // System group
@@ -1135,10 +1135,10 @@ static stat_t _do_all(nvObj_t *nv)  // print all parameters
     _do_axes(nv);
     _do_inputs(nv);
     _do_outputs(nv);
-//    _do_heaters(nv);              // there are no text mode prints for heaters
+    _do_heaters(nv);              // there are no text mode prints for heaters
     _do_group(nv, (char *)"p1");    // PWM group
     _do_offsets(nv);                // coordinate system offsets
-    return (STAT_OK);
+    return (STAT_COMPLETE);         // STAT_COMPLETE suppresses a second JSON write that would cause a fault
 }
 
 /***********************************************************************************
diff --git a/g2core/error.h b/g2core/error.h
index 5c802261..ff8ec5a0 100644
--- a/g2core/error.h
+++ b/g2core/error.h
@@ -204,7 +204,7 @@ char *get_status_message(stat_t status);
 #define STAT_MAX_DEPTH_EXCEEDED 115             // JSON exceeded maximum nesting depth
 #define STAT_VALUE_TYPE_ERROR 116               // JSON value does not agree with variable type
 
-#define STAT_INPUT_FROM_MUTED_CHANNEL_ERROR 117               // input from a muted channel was ignored
+#define STAT_INPUT_FROM_MUTED_CHANNEL_ERROR 117 // input from a muted channel was ignored
 #define STAT_ERROR_118 118
 #define STAT_ERROR_119 119
 
diff --git a/g2core/g2core.cppproj b/g2core/g2core.cppproj
index f6402809..591d31b0 100644
--- a/g2core/g2core.cppproj
+++ b/g2core/g2core.cppproj
@@ -5,7 +5,7 @@
     <ProjectVersion>7.0</ProjectVersion>
     <ToolchainName>com.Atmel.ARMGCC.CPP</ToolchainName>
     <ProjectGuid>{44ea8fec-55d7-4149-8a78-a574fc26bf51}</ProjectGuid>
-    <avrdevice>ATSAMS70N19</avrdevice>
+    <avrdevice>ATSAM3X8C</avrdevice>
     <avrdeviceseries>none</avrdeviceseries>
     <OutputType>Executable</OutputType>
     <Language>CPP</Language>
@@ -68,12 +68,12 @@
     <com_atmel_avrdbg_tool_atmelice>
       <ToolOptions>
         <InterfaceProperties>
-          <SwdClock>2000000</SwdClock>
+          <SwdClock>10000000</SwdClock>
         </InterfaceProperties>
         <InterfaceName>SWD</InterfaceName>
       </ToolOptions>
       <ToolType>com.atmel.avrdbg.tool.atmelice</ToolType>
-      <ToolNumber>J41800019454</ToolNumber>
+      <ToolNumber>J41800036434</ToolNumber>
       <ToolName>Atmel-ICE</ToolName>
     </com_atmel_avrdbg_tool_atmelice>
     <UseGdb>True</UseGdb>
@@ -100,9 +100,9 @@
       <HWProgramCounterSampling>True</HWProgramCounterSampling>
     </PercepioTrace>
     <preserveEEPROM>true</preserveEEPROM>
-    <avrtoolserialnumber>J41800019454</avrtoolserialnumber>
-    <avrdeviceexpectedsignature>0xA11D0A00</avrdeviceexpectedsignature>
-    <avrtoolinterfaceclock>2000000</avrtoolinterfaceclock>
+    <avrtoolserialnumber>J41800036434</avrtoolserialnumber>
+    <avrdeviceexpectedsignature>0x284E0A60</avrdeviceexpectedsignature>
+    <avrtoolinterfaceclock>10000000</avrtoolinterfaceclock>
     <custom>
       <ToolOptions xmlns="">
         <InterfaceProperties>
diff --git a/g2core/json_parser.cpp b/g2core/json_parser.cpp
old mode 100755
new mode 100644
index 7a8859a9..cd9a05d0
--- a/g2core/json_parser.cpp
+++ b/g2core/json_parser.cpp
@@ -568,10 +568,13 @@ void json_print_response(uint8_t status, const bool only_to_muted /*= false*/)
                     nv->valuetype = TYPE_EMPTY;
                 }
             }
-        } while ((nv = nv->nx) != NULL);
+        } while ((nv = nv->nx) != NULL);                    // Emergency escape
     }
 
-    // Footer processing
+    // Footer processing - wind to the end of the populated blocks
+    if (nv == NULL) {                                       // this can happen when processing a stale list
+        return;                                             //...that already has a null-terminated footer
+    }
     while(nv->valuetype != TYPE_EMPTY) {                    // find a free nvObj at end of the list...
         if ((nv = nv->nx) == NULL) {                        // oops! No free nvObj!
             rpt_exception(STAT_JSON_OUTPUT_TOO_LONG, "json_print_response() json too long"); // report this as an exception