ProjectExplorer: Fix crash in toolchain widget

Amends d73d5fe0b1

Fixes: QTCREATORBUG-27696
Change-Id: Id94f39cd4fc6768af3f66039f808ed7c974cfeed
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/utils/algorithm.h

@@ -76,6 +76,8 @@ bool allOf(const T &container, F predicate);
 /////////////////////////
 template<typename T, typename F>
 void erase(T &container, F predicate);
+template<typename T, typename F>
+bool eraseOne(T &container, F predicate);
 
 /////////////////////////
 // contains
@@ -442,7 +444,15 @@ void erase(T &container, F predicate)
     container.erase(std::remove_if(std::begin(container), std::end(container), predicate),
                     std::end(container));
 }
-
+template<typename T, typename F>
+bool eraseOne(T &container, F predicate)
+{
+    const auto it = std::find_if(std::begin(container), std::end(container), predicate);
+    if (it == std::end(container))
+        return false;
+    container.erase(it);
+    return true;
+}
 
 //////////////////
 // contains

src/plugins/projectexplorer/toolchainoptionspage.cpp

@@ -363,27 +363,24 @@ ToolChainTreeItem *ToolChainOptionsWidget::insertToolChain(ToolChain *tc, bool c
 
 void ToolChainOptionsWidget::addToolChain(ToolChain *tc)
 {
-    for (int i = 0; i < m_toAddList.size(); ++i) {
+    if (Utils::eraseOne(m_toAddList, [tc](const ToolChainTreeItem *item) {
-        if (m_toAddList.at(i)->toolChain == tc) {
+                        return item->toolChain == tc; })) {
-            // do not delete i element: Still used elsewhere!
+        // do not delete here!
-            m_toAddList.removeAt(i);
+        return;
-            return;
-        }
     }
 
     insertToolChain(tc);
-
     updateState();
 }
 
 void ToolChainOptionsWidget::removeToolChain(ToolChain *tc)
 {
-    for (int i = 0; i < m_toRemoveList.size(); ++i) {
+    if (auto it = std::find_if(m_toRemoveList.begin(), m_toRemoveList.end(),
-        if (m_toRemoveList.at(i)->toolChain == tc) {
+            [tc](const ToolChainTreeItem *item) { return item->toolChain == tc; });
-            m_toRemoveList.removeAt(i);
+            it != m_toRemoveList.end()) {
-            delete m_toRemoveList.at(i);
+        m_toRemoveList.erase(it);
-            return;
+        delete *it;
-        }
+        return;
     }
 
     StaticTreeItem *parent = parentForToolChain(tc);