Fix for M291 in homing file

5 files changed, 11 insertions, 19 deletions

diff --git a/src/GCodes/GCodeMachineState.h b/src/GCodes/GCodeMachineState.h
index 8a5b374a..d5b74a73 100644
--- a/src/GCodes/GCodeMachineState.h
+++ b/src/GCodes/GCodeMachineState.h
@@ -206,6 +206,8 @@ public:
 #if HAS_SBC_INTERFACE
 	FileId fileId;													// virtual ID to distinguish files in different stack levels (only unique per GB)
 #endif
+	// Note, having a bit set in lockedResources doesn't necessarily mean that we own the lock!
+	// It means we acquired the lock at this stack level, and haven't released it at this level. It may have been released at a more nested level, or stolen from us (see GrabResource).
 	ResourceBitmap lockedResources;
 	BlockState blockStates[MaxBlockIndent];
 	uint32_t lineNumber;
diff --git a/src/GCodes/GCodes.cpp b/src/GCodes/GCodes.cpp
index dbc2401f..cc0f34cf 100644
--- a/src/GCodes/GCodes.cpp
+++ b/src/GCodes/GCodes.cpp
@@ -4627,17 +4627,9 @@ void GCodes::GrabResource(const GCodeBuffer& gb, Resource r) noexcept
 
 	if (resourceOwners[r] != &gb)
 	{
-		if (resourceOwners[r] != nullptr)
-		{
-			GCodeMachineState *m = &(resourceOwners[r]->LatestMachineState());
-			do
-			{
-				m->lockedResources.ClearBit(r);
-				m = m->GetPrevious();
-			}
-			while (m != nullptr);
-		}
+		// Note, we now leave the resource bit set in the original owning GCodeBuffer machine state
 		resourceOwners[r] = &gb;
+		gb.LatestMachineState().lockedResources.SetBit(r);
 	}
 }
 
@@ -4672,12 +4664,8 @@ void GCodes::UnlockResource(const GCodeBuffer& gb, Resource r) noexcept
 
 	if (resourceOwners[r] == &gb)
 	{
-		GCodeMachineState * mc = &gb.LatestMachineState();
-		do
-		{
-			mc->lockedResources.ClearBit(r);
-			mc = mc->GetPrevious();
-		} while (mc != nullptr);
+		// Note, we leave the bit set in previous stack levels! This is needed e.g. to allow M291 blocking messages to be used in homing files.
+		gb.LatestMachineState().lockedResources.ClearBit(r);
 		resourceOwners[r] = nullptr;
 	}
 }
diff --git a/src/GCodes/GCodes2.cpp b/src/GCodes/GCodes2.cpp
index 158b8a59..62f441c2 100644
--- a/src/GCodes/GCodes2.cpp
+++ b/src/GCodes/GCodes2.cpp
@@ -1517,7 +1517,7 @@ bool GCodes::HandleMcode(GCodeBuffer& gb, const StringRef& reply) THROWS(GCodeEx
 					// 2020-02-04 Don't unlock movement if it was already locked, e.g. because M109 was used in a macro
 					if (!movementWasLocked)
 					{
-						UnlockMovement(gb);								// allow babystepping and pausing while heating
+						UnlockMovement(gb);							// allow babystepping and pausing while heating
 					}
 				}
 
diff --git a/src/GCodes/GCodes4.cpp b/src/GCodes/GCodes4.cpp
index 1170bcc3..28844f04 100644
--- a/src/GCodes/GCodes4.cpp
+++ b/src/GCodes/GCodes4.cpp
@@ -269,6 +269,7 @@ void GCodes::RunStateMachine(GCodeBuffer& gb, const StringRef& reply) noexcept
 		break;
 
 	case GCodeState::homing1:
+		// We should only ever get here when toBeHomed is not empty
 		if (toBeHomed.IsEmpty())
 		{
 			gb.SetState(GCodeState::normal);
@@ -309,7 +310,8 @@ void GCodes::RunStateMachine(GCodeBuffer& gb, const StringRef& reply) noexcept
 			// Test whether the previous homing move homed any axes
 			if (toBeHomed.Disjoint(axesHomed))
 			{
-				reply.copy("Homing failed");
+				reply.copy("Failed to home axes ");
+				AppendAxes(reply, toBeHomed);
 				stateMachineResult = GCodeResult::error;
 				toBeHomed.Clear();
 				gb.SetState(GCodeState::normal);
diff --git a/src/Version.h b/src/Version.h
index 044430ad..53b2d577 100644
--- a/src/Version.h
+++ b/src/Version.h
@@ -10,7 +10,7 @@
 
 #ifndef VERSION
 // Note: the complete VERSION string must be in standard version number format and must not contain spaces! This is so that DWC can parse it.
-# define MAIN_VERSION	"3.4.0rc2"
+# define MAIN_VERSION	"3.4.0rc2+1"
 # ifdef USE_CAN0
 #  define VERSION_SUFFIX	"(CAN0)"
 # else