fix(bank_panel): null-guard uniformity, stale comment/focus nudge on delete, dragArmed on capture-loss, menuAppend comment

src/bank_panel.cpp

@@ -991,6 +991,7 @@ std::string mintBankId() {
 }
 
 void doCreateBank() {
+    if (!book()) return;
     std::string name;
     if (!promptText("ReaSampler: create bank", "Bank name:", "", name)) return;
     const std::string id = mintBankId();
@@ -1006,6 +1007,7 @@ void doCreateBank() {
 }
 
 void doRenameBank(const std::string& bankId) {
+    if (!book()) return;
     const Bank* bk = book()->bank(bankId);
     if (!bk || bk->isPool()) return;
     const std::string current = bk->displayName;  // copy before any mutation
@@ -1024,6 +1026,7 @@ void doRenameBank(const std::string& bankId) {
 // member count AND offers evacuate as the one-click alternative (Yes=delete anyway,
 // No=evacuate-then-keep, Cancel=abort) — richer than B3's basic YESNO.
 void doDeleteBank(const std::string& bankId) {
+    if (!book()) return;
     const Bank* bk = book()->bank(bankId);
     if (!bk || bk->isPool()) return;
     const std::size_t members = bk->index.size();  // read BEFORE any mutation
@@ -1049,12 +1052,14 @@ void doDeleteBank(const std::string& bankId) {
     }
     if (!book()->deleteBank(bankId)) return;
     persistBook();
-    // shownBankId is reconciled by the next fingerprint pass; nudge focus to pool if
+    // shownBankId is reconciled by the next fingerprint pass. If no named banks remain,
-    // no named banks remain so the selection has a valid home.
+    // nudge focus to the pool so the selection has a valid home.
+    if (namedBanks().empty()) g_panel.focusedRegion = Region::Pool;
     invalidatePanel();
 }
 
 void doEvacuateBank(const std::string& bankId) {
+    if (!book()) return;
     const Bank* bk = book()->bank(bankId);
     if (!bk || bk->isPool()) return;
     if (!book()->evacuate(bankId)) return;
@@ -1063,6 +1068,7 @@ void doEvacuateBank(const std::string& bankId) {
 }
 
 void doActivateBank(const std::string& bankId) {
+    if (!book()) return;
     if (!book()->setActiveBank(bankId)) return;  // rejects an unknown id
     persistBook();
     invalidatePanel();
@@ -1073,6 +1079,7 @@ void doActivateBank(const std::string& bankId) {
 void transferSamples(const std::vector<std::string>& sampleIds,
                      const std::string& srcBankId, const std::string& destBankId,
                      bool copy) {
+    if (!book()) return;
     if (sampleIds.empty() || srcBankId == destBankId) return;
     if (!book()->bank(srcBankId) || !book()->bank(destBankId)) return;
     for (const std::string& sid : sampleIds) {
@@ -1108,9 +1115,8 @@ std::vector<std::string> focusedSelectionIds() {
 // hands the chosen id straight back, so no hookcommand routing is involved.
 
 // Appends a string item (id) to `menu` at its end. Portable over Win32/SWELL: both
-// accept InsertMenu(menu, pos, MF_BYPOSITION|MF_STRING, id, text) with pos past the
+// accept InsertMenu(menu, pos, MF_BYPOSITION|MF_STRING, id, text) with a negative
-// end appending. -1 as an unsigned position appends on Win32; SWELL clamps a large
+// position appending. Win32 and SWELL both treat pos < 0 as an append.
-// pos to the end.
 void menuAppend(HMENU menu, unsigned int id, const char* text, bool grayed = false) {
     UINT flags = MF_BYPOSITION | MF_STRING;
     if (grayed) flags |= MF_GRAYED;
@@ -1135,6 +1141,7 @@ enum : unsigned int {
 // Shows the right-click context menu for a named-bank TAB: activate / rename / delete
 // / evacuate that bank, plus a create entry. Drives the id-keyed ops.
 void showTabMenu(int screenX, int screenY, const std::string& bankId) {
+    if (!book()) return;
     const Bank* bk = book()->bank(bankId);
     if (!bk || bk->isPool()) return;
     const bool isActive = book()->activeBankId() == bankId;
@@ -1582,6 +1589,14 @@ WDL_DLGRET dlgProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
             SetFocus(hwnd);
             handleRightClick(GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam));
             return 0;
+        case WM_CAPTURECHANGED:
+            // Capture lost before a drag began (e.g. pointer left window pre-threshold
+            // and button released outside) — disarm so the state doesn't stay stale.
+            if (g_panel.dragArmed && !g_panel.dragging) {
+                g_panel.dragArmed = false;
+                invalidatePanel();
+            }
+            return 0;
         case WM_DESTROY:
             if (GetCapture() == hwnd) ReleaseCapture();
             stopAudition();