Setup Archive and testing 4 Issues for V0.2)

.gitea/ISSUE_TEMPLATE/bug_report.yaml

@@ -0,0 +1,107 @@
+name: Bug report
+about: Report a reproducible bug in the SDG2042X GUI
+title: "[Bug]: "
+labels:
+  - kind/bug
+  - state/confirmed
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Please fill this in properly. Instrument-facing bugs are annoying enough already.
+
+  - type: dropdown
+    id: version
+    attributes:
+      label: Affected version
+      description: Select the version where you saw the problem.
+      options:
+        - v0.1
+        - v0.2
+        - git / local working copy
+    validations:
+      required: true
+
+  - type: dropdown
+    id: area
+    attributes:
+      label: Area
+      description: Pick the part of the application that looks most affected.
+      options:
+        - transport
+        - gui-basic
+        - arb
+        - presets
+        - config
+        - screenshot
+        - scpi-cli
+        - burst
+        - sweep
+    validations:
+      required: true
+
+  - type: dropdown
+    id: severity
+    attributes:
+      label: Severity
+      options:
+        - high
+        - medium
+        - low
+    validations:
+      required: true
+
+  - type: textarea
+    id: summary
+    attributes:
+      label: What happened?
+      description: Describe the bug and what you expected instead.
+      placeholder: The application did X, but I expected Y.
+    validations:
+      required: true
+
+  - type: textarea
+    id: steps
+    attributes:
+      label: Steps to reproduce
+      placeholder: |
+        1. Connect to instrument
+        2. Open ARB tab
+        3. Download waveform
+        4. UI freezes
+    validations:
+      required: true
+
+  - type: input
+    id: instrument
+    attributes:
+      label: Instrument model / firmware
+      placeholder: e.g. SDG2042X, firmware x.y.z
+    validations:
+      required: false
+
+  - type: input
+    id: environment
+    attributes:
+      label: Host environment
+      placeholder: e.g. Ubuntu 24.04, Python 3.12, PyQt5
+    validations:
+      required: false
+
+  - type: textarea
+    id: logs
+    attributes:
+      label: Error text / SCPI response / traceback
+      placeholder: Paste relevant log output here
+    validations:
+      required: false
+
+  - type: checkboxes
+    id: checks
+    attributes:
+      label: Checks
+      options:
+        - label: I tested this more than once
+          required: false
+        - label: I checked whether this is already reported
+          required: true

.gitea/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Project page
+    url: https://togo-lab.io/
+    about: Project blog and notes
+  - name: Repository
+    url: https://gitea.togo-lab.io/tgohle/0003-SDG2042X-PyQt-GUI-for-Linux
+    about: Source code and releases

.gitea/ISSUE_TEMPLATE/enhancement.yaml

@@ -0,0 +1,54 @@
+name: Enhancement
+about: Suggest a useful improvement without calling it a bug
+title: "[Enhancement]: "
+labels:
+  - kind/enhancement
+  - state/confirmed
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Keep this practical. The goal is less friction, more reliability, or a clearer workflow.
+
+  - type: dropdown
+    id: area
+    attributes:
+      label: Area
+      options:
+        - transport
+        - gui-basic
+        - arb
+        - presets
+        - config
+        - screenshot
+        - scpi-cli
+        - burst
+        - sweep
+        - packaging
+        - documentation
+    validations:
+      required: true
+
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem to solve
+      placeholder: What practical annoyance are you trying to remove?
+    validations:
+      required: true
+
+  - type: textarea
+    id: proposal
+    attributes:
+      label: Proposed change
+      placeholder: Describe the change you want.
+    validations:
+      required: true
+
+  - type: textarea
+    id: benefit
+    attributes:
+      label: Expected benefit
+      placeholder: Reliability, speed, clarity, less UI freeze, fewer SCPI mistakes, etc.
+    validations:
+      required: true

.gitea/ISSUE_TEMPLATE/regression.yaml

@@ -0,0 +1,69 @@
+name: Regression
+about: Something that worked before and is now broken
+title: "[Regression]: "
+labels:
+  - kind/bug
+  - state/regression
+  - severity/high
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Use this when behaviour changed between versions or after a patch.
+
+  - type: input
+    id: last-good
+    attributes:
+      label: Last known good version
+      placeholder: e.g. v0.1
+    validations:
+      required: true
+
+  - type: input
+    id: first-bad
+    attributes:
+      label: First known bad version
+      placeholder: e.g. v0.2
+    validations:
+      required: true
+
+  - type: dropdown
+    id: area
+    attributes:
+      label: Area
+      options:
+        - transport
+        - gui-basic
+        - arb
+        - presets
+        - config
+        - screenshot
+        - scpi-cli
+        - burst
+        - sweep
+    validations:
+      required: true
+
+  - type: textarea
+    id: repro
+    attributes:
+      label: Reproduction
+      placeholder: Describe the exact steps that still worked before and now fail.
+    validations:
+      required: true
+
+  - type: textarea
+    id: impact
+    attributes:
+      label: Impact
+      placeholder: What does this break in normal use?
+    validations:
+      required: true
+
+  - type: textarea
+    id: logs
+    attributes:
+      label: Error text / SCPI response / traceback
+      placeholder: Paste relevant evidence here
+    validations:
+      required: false

script/archive/V0.0/SDG2042x.dat

@@ -0,0 +1,31 @@
+# SDG2042X presets
+SLOT1_NAME=
+SLOT1_BSWV=
+SLOT1_OUTP=
+SLOT2_NAME=
+SLOT2_BSWV=
+SLOT2_OUTP=
+SLOT3_NAME=
+SLOT3_BSWV=
+SLOT3_OUTP=
+SLOT4_NAME=
+SLOT4_BSWV=
+SLOT4_OUTP=
+SLOT5_NAME=
+SLOT5_BSWV=
+SLOT5_OUTP=
+SLOT6_NAME=
+SLOT6_BSWV=
+SLOT6_OUTP=
+SLOT7_NAME=
+SLOT7_BSWV=
+SLOT7_OUTP=
+SLOT8_NAME=
+SLOT8_BSWV=
+SLOT8_OUTP=
+SLOT9_NAME=
+SLOT9_BSWV=
+SLOT9_OUTP=
+SLOT10_NAME=
+SLOT10_BSWV=
+SLOT10_OUTP=

script/archive/V0.1/SDG2042x.dat

@@ -0,0 +1,31 @@
+# SDG2042X presets
+SLOT1_NAME=
+SLOT1_BSWV=
+SLOT1_OUTP=
+SLOT2_NAME=
+SLOT2_BSWV=
+SLOT2_OUTP=
+SLOT3_NAME=
+SLOT3_BSWV=
+SLOT3_OUTP=
+SLOT4_NAME=
+SLOT4_BSWV=
+SLOT4_OUTP=
+SLOT5_NAME=
+SLOT5_BSWV=
+SLOT5_OUTP=
+SLOT6_NAME=
+SLOT6_BSWV=
+SLOT6_OUTP=
+SLOT7_NAME=
+SLOT7_BSWV=
+SLOT7_OUTP=
+SLOT8_NAME=
+SLOT8_BSWV=
+SLOT8_OUTP=
+SLOT9_NAME=
+SLOT9_BSWV=
+SLOT9_OUTP=
+SLOT10_NAME=
+SLOT10_BSWV=
+SLOT10_OUTP=

script/archive/V0.2/SDG2042x.dat

@@ -0,0 +1,31 @@
+# SDG2042X presets
+SLOT1_NAME=
+SLOT1_BSWV=
+SLOT1_OUTP=
+SLOT2_NAME=
+SLOT2_BSWV=
+SLOT2_OUTP=
+SLOT3_NAME=
+SLOT3_BSWV=
+SLOT3_OUTP=
+SLOT4_NAME=
+SLOT4_BSWV=
+SLOT4_OUTP=
+SLOT5_NAME=
+SLOT5_BSWV=
+SLOT5_OUTP=
+SLOT6_NAME=
+SLOT6_BSWV=
+SLOT6_OUTP=
+SLOT7_NAME=
+SLOT7_BSWV=
+SLOT7_OUTP=
+SLOT8_NAME=
+SLOT8_BSWV=
+SLOT8_OUTP=
+SLOT9_NAME=
+SLOT9_BSWV=
+SLOT9_OUTP=
+SLOT10_NAME=
+SLOT10_BSWV=
+SLOT10_OUTP=

script/archive/V0.2/test_v02_Issue_1-2-6-12/TEST_PROCEDURE_v0.2_Issue_1-2-6-12.md

@@ -0,0 +1,97 @@
+# SDG2042X v0.2 — Test Procedure
+**Milestone:** v0.2.0 - first bugfix round  
+**Issues:** #1 · #2 · #6 · #12  
+**Date:** 2026-04-18
+
+---
+
+## Files Required
+
+| File | Purpose |
+|------|---------|
+| `SDG2042X_V0.2.py` | Script under test |
+| `test_v0.2_all.py` | Automated test suite |
+
+Both files must be in the **same directory**.
+
+---
+
+## Part 1 — Automated Tests (no instrument required)
+
+Covers: **#1** `_recv_line()` · **#6** screenshot path · **#12** `human_to_eng()`  
+Covers structurally: **#2** ARB thread (AST check)
+
+### Run
+
+```bash
+cd /path/to/scripts
+python3 test_v0.2_all.py
+```
+
+Single issue:
+
+```bash
+python3 test_v0.2_all.py --issue 12
+```
+
+### Expected output
+
+```
+Issue #1   PASS (5/5)
+Issue #12  PASS (20/20)
+Issue #2   PASS (8/8)
+Issue #6   PASS (2/2)
+
+Total: 35/35 passed
+✓ All tests passed — safe to close all four issues
+```
+
+Exit code `0` = pass, `1` = fail. Suitable for CI.
+
+### Close criteria
+
+All 35 TCs green → close **#1, #6, #12** immediately.  
+**#2** additionally requires the hardware test below.
+
+---
+
+## Part 2 — Hardware Test (instrument required)
+
+Covers: **#2** ARB download GUI responsiveness
+
+### Setup
+
+- SDG2042X powered and reachable on LAN
+- At least one USER waveform stored on the instrument  
+  *(if none: upload any `.bin` via ARB Manager → Upload first)*
+
+### Procedure
+
+| Step | Action | Expected |
+|------|--------|---------|
+| 1 | Start GUI: `python3 SDG2042X_V0.2.py --ip <addr>` | Window opens |
+| 2 | Click **Connect** | Log: `Connected to <addr>:5025` |
+| 3 | Tab **ARB Manager** → click **Refresh** | USER list populated |
+| 4 | Select a USER waveform → click **Download USER → file** | Log: `ARB download started…` |
+| 5 | **While download runs**: click IDN?, change waveform combo, click SYST:ERR? | UI responds immediately — no freeze |
+| 6 | Wait for completion | Log: `Downloaded -> <path> (N bytes)` |
+| 7 | Verify saved file: `ls -lh <saved_file>` | Non-zero size |
+
+### Close criteria
+
+Steps 5 and 6 both pass → close **#2**.
+
+---
+
+## Summary Checklist
+
+```
+[ ] python3 test_v0.2_all.py  →  35/35
+[ ] #1  close
+[ ] #6  close
+[ ] #12 close
+[ ] Hardware test step 5: GUI responsive during ARB download
+[ ] Hardware test step 6: file saved, non-zero size
+[ ] #2  close
+[ ] Milestone v0.2.0 → mark closed
+```

script/archive/V0.2/test_v02_Issue_1-2-6-12/test_v0.2_Issue_1-2-6-12 (results - passed).md

@@ -0,0 +1,69 @@
+SDG2042X v0.2 — regression test suite
+Script under test: /home/tgohle/TGONet_Virtual/tgo-files/git/ToGo-Lab/0003-SDG2042X-PyQt-GUI-for-Linux/script/test_v02_Issue_1-2-6-12/./SDG2042X_V0.2.py
+
+── Issue #12 — human_to_eng() MHz regression ──
+  [  OK  ] BUG-REG: 1.5 MHz → 1500000 (was 0.0000015)
+  [  OK  ] BUG-REG: 30 MHz → 30000000
+  [  OK  ] BUG-REG: 100 MHz → 100000000
+  [  OK  ] 1 kHz
+  [  OK  ] 10 kHz
+  [  OK  ] 100 Hz
+  [  OK  ] 1 GHz
+  [  OK  ] lowercase hz
+  [  OK  ] uppercase KHZ
+  [  OK  ] 500 ms
+  [  OK  ] 1 us
+  [  OK  ] 250 ns
+  [  OK  ] 2.5 V
+  [  OK  ] 500 mV
+  [  OK  ] 1.0 Vpp
+  [  OK  ] bare integer
+  [  OK  ] bare float
+  [  OK  ] scientific notation
+  [  OK  ] non-numeric fallback
+  [  OK  ] empty string
+
+── Issue #1 — _recv_line() handles partial TCP receive ──
+  [  OK  ] TC-1a single chunk
+  [  OK  ] TC-1b newline split into own chunk
+  [  OK  ] TC-1c byte-by-byte
+  [  OK  ] TC-1d split at midpoint
+  [  OK  ] TC-1e empty response returns empty string
+
+── Issue #6 — on_screenshot() uses in-memory cfg, not disk config ──
+  [  OK  ] TC-6a: worker receives self.cfg path, not load_config() path
+         disk cfg  = /tmp/tmpy6m9nh8m/dir_disk
+         self.cfg  = /tmp/tmpy6m9nh8m/dir_memory
+         received  = /tmp/tmpy6m9nh8m/dir_memory
+  [  OK  ] TC-6b: worker path differs from stale disk path
+
+── Issue #2 — ARB download moved to QThread (structural) ──
+  [  OK  ] TC-2a: class ARBDownloadWorker exists
+  [  OK  ] TC-2b: ARBDownloadWorker inherits QThread
+  [  OK  ] TC-2c: ARBDownloadWorker.run() defined
+  [  OK  ] TC-2d: recv() call inside ARBDownloadWorker.run()
+  [  OK  ] TC-2e: on_arb_download() contains no blocking while loop
+  [  OK  ] TC-2f: on_arb_download() calls worker.start()
+  [  OK  ] TC-2g: _on_arb_download_done() handler defined
+  [  OK  ] TC-2h: done signal connected to handler
+
+  NOTE: live GUI responsiveness during download requires
+  a connected SDG2042X — run manually per test strategy.
+
+══════════════════════════════════════════════
+  SUMMARY
+══════════════════════════════════════════════
+  Issue #1   PASS (5/5)
+  Issue #12  PASS (20/20)
+  Issue #2   PASS (8/8)
+  Issue #6   PASS (2/2)
+
+  Total: 35/35 passed
+  ✓ All tests passed — safe to close all four issues
+
+  Gitea close checklist:
+    #1   ✓ close
+    #2   ✓ close
+    #6   ✓ close
+    #12  ✓ close
+

script/archive/V0.2/test_v02_Issue_1-2-6-12/test_v0.2_Issue_1-2-6-12.py

@@ -0,0 +1,476 @@
+#!/usr/bin/env python3
+"""
+test_v0.2_all.py  --  SDG2042X v0.2 regression test suite
+Tests: Issue #1, #2, #6, #12  (milestone: v0.2.0 - first bugfix round finished)
+
+Usage:
+    python3 test_v0.2_all.py              # run all tests
+    python3 test_v0.2_all.py --issue 12   # run single issue
+
+Place this file next to SDG2042X_V0.2.py and run from that directory.
+No instrument required. All tests are offline / mocked.
+
+Author: ToGo-Lab test suite — generated 2026-04-18
+"""
+
+import ast
+import importlib.util
+import os
+import re
+import socket
+import sys
+import tempfile
+import threading
+import time
+import types
+
+SCRIPT_NAME = "SDG2042X_V0.2.py"
+
+# ─────────────────────────────────────────────────────────────────────────────
+# ANSI colours (disabled on Windows)
+# ─────────────────────────────────────────────────────────────────────────────
+USE_COLOUR = sys.platform != "win32"
+def _c(code, s): return f"\033[{code}m{s}\033[0m" if USE_COLOUR else s
+OK   = lambda s: _c("32;1", s)
+FAIL = lambda s: _c("31;1", s)
+HEAD = lambda s: _c("36;1", s)
+DIM  = lambda s: _c("2",    s)
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Result collector
+# ─────────────────────────────────────────────────────────────────────────────
+results: dict[str, list[tuple[bool, str]]] = {}
+
+def record(issue: str, ok: bool, label: str, detail: str = ""):
+    results.setdefault(issue, []).append((ok, label))
+    mark = OK("  OK  ") if ok else FAIL(" FAIL ")
+    print(f"  [{mark}] {label}")
+    if detail:
+        for line in detail.strip().splitlines():
+            print(DIM(f"         {line}"))
+
+def section(title: str):
+    print()
+    print(HEAD(f"── {title} ──"))
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Locate the script under test
+# ─────────────────────────────────────────────────────────────────────────────
+def find_script() -> str:
+    candidate = os.path.join(os.path.dirname(__file__), SCRIPT_NAME)
+    if not os.path.exists(candidate):
+        sys.exit(FAIL(f"ERROR: {SCRIPT_NAME} not found next to this test file.\n"
+                      f"Expected: {candidate}"))
+    return candidate
+
+SCRIPT_PATH = find_script()
+SRC = open(SCRIPT_PATH, encoding="utf-8").read()
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Minimal PyQt5 mock so the module can be imported without a display
+# ─────────────────────────────────────────────────────────────────────────────
+def _install_pyqt5_mock():
+    def _noop(*a, **k): return None
+    def _cls(name): return type(name, (), {
+        "__init__": _noop, "__call__": _noop,
+        "setEnabled": _noop, "addItems": _noop, "setText": _noop,
+        "text": lambda s: "", "currentText": lambda s: "",
+        "appendPlainText": _noop, "setReadOnly": _noop,
+        "setMinimumHeight": _noop, "setPlaceholderText": _noop,
+        "setWindowTitle": _noop, "resize": _noop, "show": _noop,
+        "setRange": _noop, "setValue": _noop, "value": lambda s: 1,
+        "addWidget": _noop, "setLayout": _noop, "addStretch": _noop,
+        "setColumnStretch": _noop, "setHorizontalHeaderLabels": _noop,
+        "horizontalHeader": lambda s: type("h",(),{"setStretchLastSection":_noop})(),
+        "verticalHeader": lambda s: type("v",(),{"setVisible":_noop})(),
+        "setItem": _noop, "item": lambda s,r,c: type("i",(),{"setFlags":_noop,"setText":_noop,"text":lambda ss:""})(),
+        "setFlags": _noop, "clicked": type("sig",(),{"connect":_noop})(),
+        "currentTextChanged": type("sig",(),{"connect":_noop})(),
+        "returnPressed": type("sig",(),{"connect":_noop})(),
+        "isRunning": lambda s: False, "start": _noop,
+        "done": type("sig",(),{"connect":_noop, "emit":_noop})(),
+        "isNull": lambda s: True,
+    })
+
+    # Build mock modules
+    for mod in ["PyQt5","PyQt5.QtWidgets","PyQt5.QtCore","PyQt5.QtGui"]:
+        if mod not in sys.modules:
+            sys.modules[mod] = types.ModuleType(mod)
+
+    qw = sys.modules["PyQt5.QtWidgets"]
+    qc = sys.modules["PyQt5.QtCore"]
+    qg = sys.modules["PyQt5.QtGui"]
+
+    for name in ["QWidget","QLabel","QLineEdit","QComboBox","QPushButton",
+                 "QPlainTextEdit","QTabWidget","QGridLayout","QHBoxLayout",
+                 "QVBoxLayout","QApplication","QSpinBox","QCheckBox",
+                 "QListWidget","QTableWidget","QTableWidgetItem",
+                 "QFileDialog","QSizePolicy"]:
+        setattr(qw, name, _cls(name))
+
+    # QThread: base for workers
+    setattr(qc, "QThread", _cls("QThread"))
+    setattr(qc, "Qt", type("Qt", (), {"WaitCursor": 0, "ItemIsEnabled": 0}))
+
+    class _Signal:
+        def __init__(self, *types): pass
+        def connect(self, fn): pass
+        def emit(self, *a): pass
+    setattr(qc, "pyqtSignal", _Signal)
+
+    setattr(qg, "QImage",  _cls("QImage"))
+    setattr(qg, "QPixmap", _cls("QPixmap"))
+
+_install_pyqt5_mock()
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Load module under test (SDG2042X_V0.2.py)
+# ─────────────────────────────────────────────────────────────────────────────
+spec = importlib.util.spec_from_file_location("sdg", SCRIPT_PATH)
+sdg  = importlib.util.module_from_spec(spec)
+try:
+    spec.loader.exec_module(sdg)
+except Exception as e:
+    sys.exit(FAIL(f"ERROR: failed to import {SCRIPT_NAME}: {e}"))
+
+
+# ═════════════════════════════════════════════════════════════════════════════
+# ISSUE #12 — human_to_eng() MHz regression
+# ═════════════════════════════════════════════════════════════════════════════
+def test_issue_12():
+    section("Issue #12 — human_to_eng() MHz regression")
+
+    fn = sdg.human_to_eng
+
+    cases = [
+        # (input, expected, description)
+        # ── THE BUG: these were silently wrong before v0.2 ──
+        ("1.5 MHz",   "1500000",      "BUG-REG: 1.5 MHz → 1500000 (was 0.0000015)"),
+        ("30 MHz",    "30000000",     "BUG-REG: 30 MHz → 30000000"),
+        ("100 MHz",   "100000000",    "BUG-REG: 100 MHz → 100000000"),
+        # ── Frequency ──
+        ("1 kHz",     "1000",         "1 kHz"),
+        ("10 kHz",    "10000",        "10 kHz"),
+        ("100 Hz",    "100",          "100 Hz"),
+        ("1 GHz",     "1000000000",   "1 GHz"),
+        ("1 hz",      "1",            "lowercase hz"),
+        ("1 KHZ",     "1000",         "uppercase KHZ"),
+        # ── Time ──
+        ("500 ms",    "0.5",          "500 ms"),
+        ("1 us",      "1e-06",        "1 us"),
+        ("250 ns",    repr(250e-9),   "250 ns"),
+        # ── Voltage ──
+        ("2.5 V",     "2.5",          "2.5 V"),
+        ("500 mV",    "0.5",          "500 mV"),
+        ("1.0 Vpp",   "1",            "1.0 Vpp"),
+        # ── Bare numbers (duty, phase, offset) ──
+        ("50",        "50",           "bare integer"),
+        ("0.001",     "0.001",        "bare float"),
+        ("1e-6",      "1e-06",        "scientific notation"),
+        # ── Fallback ──
+        ("SINE",      "SINE",         "non-numeric fallback"),
+        ("",          "",             "empty string"),
+    ]
+
+    def _eq(a, b):
+        """String equality first; fall back to float comparison for IEEE 754 noise."""
+        if a == b:
+            return True
+        try:
+            return abs(float(a) - float(b)) <= 1e-12 * max(abs(float(b)), 1e-30)
+        except (ValueError, TypeError):
+            return False
+
+    for inp, expected, desc in cases:
+        result = fn(inp)
+        ok = _eq(result, expected)
+        record("12", ok, desc,
+               f"input={inp!r}  expected≈{expected!r}  got={result!r}" if not ok else "")
+
+
+# ═════════════════════════════════════════════════════════════════════════════
+# ISSUE #1 — _recv_line() partial TCP receive
+# ═════════════════════════════════════════════════════════════════════════════
+def _fragmented_server(host, port, response: bytes, chunk_sizes: list, ready: threading.Event):
+    """Mini TCP server: sends response in deliberate fragments."""
+    srv = socket.create_server((host, port))
+    srv.settimeout(5)
+    ready.set()
+    try:
+        conn, _ = srv.accept()
+        offset = 0
+        for size in chunk_sizes:
+            conn.sendall(response[offset:offset + size])
+            offset += size
+            time.sleep(0.012)
+        if offset < len(response):
+            conn.sendall(response[offset:])
+        conn.close()
+    finally:
+        srv.close()
+
+def _next_port(base=15025):
+    """Find a free port starting from base."""
+    for p in range(base, base + 100):
+        try:
+            s = socket.create_server(("127.0.0.1", p)); s.close(); return p
+        except OSError:
+            continue
+    raise RuntimeError("No free port found")
+
+def test_issue_1():
+    section("Issue #1 — _recv_line() handles partial TCP receive")
+
+    def run_tc(label, response: bytes, chunk_sizes: list):
+        port  = _next_port()
+        ready = threading.Event()
+        t = threading.Thread(
+            target=_fragmented_server,
+            args=("127.0.0.1", port, response, chunk_sizes, ready),
+            daemon=True)
+        t.start()
+        ready.wait(timeout=2)
+
+        io = sdg.SDGLan()
+        try:
+            io.connect("127.0.0.1", port)
+            result = io._recv_line()
+        finally:
+            io.close()
+        t.join(timeout=3)
+
+        expected = response.decode("ascii").strip()
+        ok = result.strip() == expected
+        record("1", ok, label,
+               f"expected={expected!r}  got={result.strip()!r}" if not ok else "")
+
+    # TC-1a: single chunk (baseline)
+    run_tc("TC-1a single chunk",
+           b"C1:BSWV WVTP,SINE,FRQ,1000\n", [])
+
+    # TC-1b: \n arrives in a separate recv() — the original bug
+    msg = b"C1:BSWV WVTP,SINE,FRQ,1000\n"
+    run_tc("TC-1b newline split into own chunk",
+           msg, [len(msg) - 1])
+
+    # TC-1c: byte-by-byte fragmentation
+    msg = b"*IDN? Siglent,SDG2042X\n"
+    run_tc("TC-1c byte-by-byte",
+           msg, [1] * (len(msg) - 1))
+
+    # TC-1d: two unequal halves
+    msg = b"C1:OUTP ON\n"
+    run_tc("TC-1d split at midpoint",
+           msg, [len(msg) // 2])
+
+    # TC-1e: empty response (server closes immediately — must not hang)
+    port  = _next_port()
+    ready = threading.Event()
+    def empty_server():
+        srv = socket.create_server(("127.0.0.1", port)); srv.settimeout(5)
+        ready.set()
+        conn, _ = srv.accept(); conn.close(); srv.close()
+    t = threading.Thread(target=empty_server, daemon=True); t.start()
+    ready.wait(timeout=2)
+    io = sdg.SDGLan()
+    try:
+        io.connect("127.0.0.1", port)
+        result = io._recv_line()
+    finally:
+        io.close()
+    t.join(timeout=3)
+    record("1", result == "", "TC-1e empty response returns empty string",
+           f"got={result!r}" if result != "" else "")
+
+
+# ═════════════════════════════════════════════════════════════════════════════
+# ISSUE #6 — Screenshot path uses stale disk config
+# ═════════════════════════════════════════════════════════════════════════════
+def test_issue_6():
+    section("Issue #6 — on_screenshot() uses in-memory cfg, not disk config")
+
+    with tempfile.TemporaryDirectory() as tmp:
+        dir_disk   = os.path.join(tmp, "dir_disk");    os.makedirs(dir_disk)
+        dir_memory = os.path.join(tmp, "dir_memory");  os.makedirs(dir_memory)
+
+        # Write a config file pointing at dir_disk
+        cfg_path = os.path.join(tmp, "SDG2042x.config")
+        with open(cfg_path, "w") as f:
+            f.write(f"SCREENSHOT_DIR={dir_disk}\nPRESET_DIR={tmp}\n")
+
+        captured = {}
+
+        # Patch load_config to return disk dir (simulates on-disk state)
+        _orig_load = sdg.load_config
+        sdg.load_config = lambda p: {"PRESET_DIR": tmp, "SCREENSHOT_DIR": dir_disk}
+
+        # Patch ScreenshotWorker: capture outdir, don't actually run
+        class FakeWorker:
+            def __init__(self, io, outdir, parent=None):
+                captured["outdir"] = outdir
+            def isRunning(self): return False
+            def start(self): pass
+            done = type("sig", (), {"connect": lambda s, f: None})()
+        sdg.ScreenshotWorker = FakeWorker
+
+        # Minimal stand-in for Main instance with in-memory cfg = dir_memory
+        class FakeMain:
+            cfg     = {"SCREENSHOT_DIR": dir_memory, "PRESET_DIR": tmp}
+            i       = type("io", (), {"sock": object()})()
+            _scr_worker = None
+            log     = type("log", (), {"appendPlainText": lambda s, t: None})()
+            def logln(self, s): pass
+            def setCursor(self, c): pass
+            def unsetCursor(self): pass
+            def _on_screenshot_done(self, *a): pass
+            btn_scr = type("btn", (), {
+                "setEnabled": lambda s, v: None,
+                "isRunning":  lambda s: False})()
+
+        obj = FakeMain()
+        sdg.Main.on_screenshot(obj)
+
+        sdg.load_config = _orig_load
+
+        used = captured.get("outdir", "NOT_CAPTURED")
+
+        # TC-6a: worker must receive the in-memory dir, not the disk dir
+        record("6",
+               used == dir_memory,
+               "TC-6a: worker receives self.cfg path, not load_config() path",
+               f"disk cfg  = {dir_disk}\n"
+               f"self.cfg  = {dir_memory}\n"
+               f"received  = {used}")
+
+        # TC-6b: inverse sanity — must NOT be the disk path
+        record("6",
+               used != dir_disk,
+               "TC-6b: worker path differs from stale disk path",
+               f"got {used!r}, must not be {dir_disk!r}" if used == dir_disk else "")
+
+
+# ═════════════════════════════════════════════════════════════════════════════
+# ISSUE #2 — ARB download blocks GUI thread (structural AST check)
+# ═════════════════════════════════════════════════════════════════════════════
+def test_issue_2():
+    section("Issue #2 — ARB download moved to QThread (structural)")
+
+    tree = ast.parse(SRC)
+    fn_names = {n.name for n in ast.walk(tree) if isinstance(n, ast.FunctionDef)}
+
+    # TC-2a: ARBDownloadWorker class exists
+    worker_nodes = [n for n in ast.walk(tree)
+                    if isinstance(n, ast.ClassDef) and n.name == "ARBDownloadWorker"]
+    record("2", bool(worker_nodes), "TC-2a: class ARBDownloadWorker exists")
+
+    if worker_nodes:
+        worker = worker_nodes[0]
+        bases  = [getattr(b, "attr", getattr(b, "id", "")) for b in worker.bases]
+        # TC-2b: inherits QThread
+        record("2", "QThread" in bases,
+               "TC-2b: ARBDownloadWorker inherits QThread",
+               f"bases found: {bases}" if "QThread" not in bases else "")
+
+        # TC-2c: has a run() method
+        run_methods = [n for n in ast.walk(worker)
+                       if isinstance(n, ast.FunctionDef) and n.name == "run"]
+        record("2", bool(run_methods), "TC-2c: ARBDownloadWorker.run() defined")
+
+        if run_methods:
+            run_src = ast.get_source_segment(SRC, run_methods[0]) or ""
+            # TC-2d: recv is inside the worker's run(), i.e. the work is off-thread
+            record("2", "recv" in run_src,
+                   "TC-2d: recv() call inside ARBDownloadWorker.run()",
+                   "No recv() found in run() body" if "recv" not in run_src else "")
+
+    # TC-2e: on_arb_download in Main has NO while loop (blocking recv removed)
+    for node in ast.walk(tree):
+        if isinstance(node, ast.FunctionDef) and node.name == "on_arb_download":
+            has_while = any(isinstance(n, ast.While) for n in ast.walk(node))
+            record("2", not has_while,
+                   "TC-2e: on_arb_download() contains no blocking while loop",
+                   "while loop still present — BUG NOT FIXED" if has_while else "")
+
+            # TC-2f: calls .start() to launch the thread
+            call_attrs = [getattr(n.func, "attr", "")
+                          for n in ast.walk(node) if isinstance(n, ast.Call)]
+            record("2", "start" in call_attrs,
+                   "TC-2f: on_arb_download() calls worker.start()",
+                   f"call attrs found: {call_attrs}" if "start" not in call_attrs else "")
+
+    # TC-2g: result handler exists
+    record("2", "_on_arb_download_done" in fn_names,
+           "TC-2g: _on_arb_download_done() handler defined")
+
+    # TC-2h: done signal connected to handler
+    record("2", "_on_arb_download_done" in SRC and "done.connect" in SRC,
+           "TC-2h: done signal connected to handler")
+
+    print()
+    print(DIM("  NOTE: live GUI responsiveness during download requires"))
+    print(DIM("  a connected SDG2042X — run manually per test strategy."))
+
+
+# ═════════════════════════════════════════════════════════════════════════════
+# Summary
+# ═════════════════════════════════════════════════════════════════════════════
+def print_summary():
+    print()
+    print(HEAD("══════════════════════════════════════════════"))
+    print(HEAD("  SUMMARY"))
+    print(HEAD("══════════════════════════════════════════════"))
+
+    total_ok = total_fail = 0
+    issue_verdict = {}
+
+    for issue, tcs in sorted(results.items()):
+        ok_count   = sum(1 for ok, _ in tcs if ok)
+        fail_count = sum(1 for ok, _ in tcs if not ok)
+        total_ok   += ok_count
+        total_fail += fail_count
+        verdict = "PASS" if fail_count == 0 else "FAIL"
+        issue_verdict[issue] = verdict
+        v_str = OK(f"PASS ({ok_count}/{len(tcs)})") if verdict == "PASS" \
+                else FAIL(f"FAIL ({fail_count} failed)")
+        print(f"  Issue #{issue:2s}  {v_str}")
+
+    print()
+    overall = total_fail == 0
+    total   = total_ok + total_fail
+    print(f"  Total: {total_ok}/{total} passed")
+    if overall:
+        print(OK("  ✓ All tests passed — safe to close all four issues"))
+    else:
+        print(FAIL(f"  ✗ {total_fail} test(s) failed — do NOT close affected issues"))
+
+    print()
+    print("  Gitea close checklist:")
+    for iss in ["1", "2", "6", "12"]:
+        v = issue_verdict.get(iss, "NOT RUN")
+        box = OK("✓ close") if v == "PASS" else FAIL("✗ keep open")
+        print(f"    #{iss:2s}  {box}")
+    print()
+
+    return overall
+
+
+# ═════════════════════════════════════════════════════════════════════════════
+# Entry point
+# ═════════════════════════════════════════════════════════════════════════════
+if __name__ == "__main__":
+    target = None
+    if "--issue" in sys.argv:
+        idx = sys.argv.index("--issue")
+        if idx + 1 < len(sys.argv):
+            target = sys.argv[idx + 1]
+
+    print(HEAD(f"SDG2042X v0.2 — regression test suite"))
+    print(DIM(f"Script under test: {SCRIPT_PATH}"))
+
+    if target in (None, "12"): test_issue_12()
+    if target in (None, "1"):  test_issue_1()
+    if target in (None, "6"):  test_issue_6()
+    if target in (None, "2"):  test_issue_2()
+
+    ok = print_summary()
+    sys.exit(0 if ok else 1)