Fix M03 spindle-speed recovery for resume-at-line

CHANGELOG.md

@@ -17,6 +17,7 @@
 - Enhancement: Advanced TLO Calibration option. Here you can set the offset to use from tool setter, and/or the number of repeat probings to use
 - Enhancement: Added a warning popup if the controller version is lower than the firmware. This is not a supported config
 - Enhancement: Added Auto Ext. Out toggle to spindle dropdown and Config and Run screen. This can be used to automatically run a vacuum or compressor when the spindle is running
+- Fixed: Resume-at-line restores spindle speed from zero-padded M03 commands
 - Fixed: Restore Keyboard Jogging state after Probing Popup is closed
 - Fixed: Repeated firmware checks now happen just once
 - Fixed: UI widget updates from the SerialMonitor() now dispatched via the main thread. This should reduce the number of RecycleView related crashes

carveracontroller/Controller.py

@@ -765,85 +765,47 @@ def _find_m3_spindle_speed(self, lines, start_line):
             if start_line < 1 or start_line > len(lines):
                 return None
 
-            # First, find the most recent M3 command and check if it has S parameter
+            # First, find the most recent M3 command and check if it has S parameter.
+            # Token matching normalizes zero-padded forms such as M03 without
+            # confusing other M-codes such as M30.
             most_recent_m3_line = None
             for i in range(start_line - 2, -1, -1):
-                original_line = lines[i]
-                line = original_line.strip()
-
-                # Remove comments using string methods
-                if ";" in line:
-                    line = line[: line.index(";")]
-                # Remove parentheses comments using string methods
-                while "(" in line and ")" in line:
-                    start_paren = line.index("(")
-                    end_paren = line.index(")", start_paren)
-                    line = line[:start_paren] + line[end_paren + 1 :]
-
-                line = line.strip()
-                if not line:
-                    continue
-
-                # Check if line contains M3 (not M30, M31, etc.)
-                line_upper = line.upper()
-                # Use regex to find M3 that's not part of M30, M31, etc.
-                # Look for M3 that's not followed by a digit (to avoid M30, M31, etc.)
-                # M3 can be preceded by anything (including digits from other commands like S12000).
-                # Yes, really! One of the example files (ACRYLIC-R2D2.nc) has "G0X0.000Y0.000S12000M3" wtf is that!!?
-                m3_match = re.search(r"M3(?![0-9])", line_upper)
-                if m3_match:
+                has_m3, spindle_speed = self._m3_spindle_speed_from_line(lines[i])
+                if has_m3:
                     most_recent_m3_line = i
-                    # Extract S parameter from this line (S can appear before or after M3)
-                    s_match = re.search(r"S(\d+)", line)
-                    if s_match:
-                        try:
-                            spindle_speed = float(s_match.group(1))
-                            return spindle_speed
-                        except (ValueError, TypeError):
-                            pass
+                    if spindle_speed is not None:
+                        return spindle_speed
                     # Found M3 but no S parameter, continue searching backwards
                     break
 
             # If we found M3 but no S parameter, search backwards for previous M3 with S
             if most_recent_m3_line is not None:
                 for i in range(most_recent_m3_line - 1, -1, -1):
-                    original_line = lines[i]
-                    line = original_line.strip()
-
-                    # Remove comments using string methods
-                    if ";" in line:
-                        line = line[: line.index(";")]
-                    # Remove parentheses comments using string methods
-                    while "(" in line and ")" in line:
-                        start_paren = line.index("(")
-                        end_paren = line.index(")", start_paren)
-                        line = line[:start_paren] + line[end_paren + 1 :]
-
-                    line = line.strip()
-                    if not line:
-                        continue
-
-                    # Check if line contains M3 (not M30, M31, etc.)
-                    line_upper = line.upper()
-                    # Use regex to find M3 that's not part of M30, M31, etc.
-                    # Look for M3 that's not followed by a digit (to avoid M30, M31, etc.)
-                    m3_match = re.search(r"M3(?![0-9])", line_upper)
-                    if m3_match:
-                        # Extract S parameter from this line (S can appear before or after M3)
-                        s_match = re.search(r"S(\d+)", line)
-                        if s_match:
-                            try:
-                                spindle_speed = float(s_match.group(1))
-                                return spindle_speed
-                            except (ValueError, TypeError):
-                                continue
+                    has_m3, spindle_speed = self._m3_spindle_speed_from_line(lines[i])
+                    if has_m3 and spindle_speed is not None:
+                        return spindle_speed
 
             return None
 
         except Exception as e:
             logger.warning(f"Error finding M3 spindle speed before line {start_line}: {e}")
             return None
 
+    def _m3_spindle_speed_from_line(self, line):
+        tokens = self._gcode_line_to_cmd_tokens(line)
+        has_m3 = any(self._command_token_matches_base(token, "M3") for token in tokens)
+        if not has_m3:
+            return (False, None)
+
+        for token in reversed(tokens):
+            if token[:1].upper() != "S":
+                continue
+            try:
+                return (True, float(token[1:]))
+            except (ValueError, TypeError):
+                continue
+        return (True, None)
+
     def _find_last_feed_rate(self, lines=None, start_line=None, feed_lookup=None):
         """
         Return the feed rate (mm/min) in effect at start_line. Uses either pre-parsed

tests/unit/test_resume_m03_speed.py

@@ -0,0 +1,36 @@
+"""Tests for resume-at-line spindle-speed recovery."""
+
+import pytest
+
+from carveracontroller.Controller import Controller
+
+
+@pytest.mark.parametrize(
+    ("lines", "start_line", "expected"),
+    (
+        (["M03 S12000\n", "G1 X1\n"], 2, 12000.0),
+        (["S8000M03\n", "G1 X1\n"], 2, 8000.0),
+        (["M03 S6000\n", "M03\n", "G1 X1\n"], 3, 6000.0),
+        (["M3 S7000\n", "M030 S9999\n", "G1 X1\n"], 3, 7000.0),
+        (["M03 S5000\n", "G1 X1 (M03 S9999)\n", "G1 X2\n"], 3, 5000.0),
+    ),
+)
+def test_recovers_speed_from_zero_padded_m03(lines, start_line, expected):
+    controller = Controller.__new__(Controller)
+
+    assert controller._find_m3_spindle_speed(lines, start_line) == expected
+
+
+def test_resume_preview_includes_m03_speed():
+    controller = Controller.__new__(Controller)
+    controller._get_line_position_from_gcode_viewer = lambda _line: (None, None, None, None)
+    lines = [
+        "M03 S12000\n",
+        "G1 X1 F100\n",
+        "G1 X2\n",
+    ]
+
+    commands = controller.playStartLineCommand("job.nc", 3, preview=True, lines=lines)
+
+    assert "buffer M3 S12000" in commands
+    assert "buffer M3" not in commands