shiboken6/Type system parser: Purge empty code snippets

Newline characters in conjunction with <insert-template> cause empty
snippets to be added. Add functions to purge them.

Task-number: PYSIDE-1766
Change-Id: I534de369b45c4e785a643f6539a5c7fb395909f2
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Tismer <tismer@stackless.com>
(cherry picked from commit 26a1b40e4fa878a11995528dcf04158b44477477)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

3 files changed, 34 insertions, 0 deletions

diff --git a/sources/shiboken6/ApiExtractor/modifications.cpp b/sources/shiboken6/ApiExtractor/modifications.cpp
index a1c8eabbc..bb1e7505e 100644
--- a/sources/shiboken6/ApiExtractor/modifications.cpp
+++ b/sources/shiboken6/ApiExtractor/modifications.cpp
@@ -83,11 +83,29 @@ void CodeSnipAbstract::addCode(const QString &code)
     codeList.append(CodeSnipFragment(fixSpaces(code)));
 }
 
+void CodeSnipAbstract::purgeEmptyFragments()
+{
+    auto end = std::remove_if(codeList.begin(), codeList.end(),
+                              [](const CodeSnipFragment &f) { return f.isEmpty(); });
+    codeList.erase(end, codeList.end());
+}
+
 QRegularExpression CodeSnipAbstract::placeHolderRegex(int index)
 {
     return QRegularExpression(QLatin1Char('%') + QString::number(index) + QStringLiteral("\\b"));
 }
 
+void purgeEmptyCodeSnips(QList<CodeSnip> *list)
+{
+    for (auto it = list->begin(); it != list->end(); ) {
+        it->purgeEmptyFragments();
+        if (it->isEmpty())
+            it = list->erase(it);
+        else
+            ++it;
+    }
+}
+
 // ---------------------- Modification
 QString FunctionModification::accessModifierString() const
 {
diff --git a/sources/shiboken6/ApiExtractor/modifications.h b/sources/shiboken6/ApiExtractor/modifications.h
index 3435c9737..6761671c7 100644
--- a/sources/shiboken6/ApiExtractor/modifications.h
+++ b/sources/shiboken6/ApiExtractor/modifications.h
@@ -116,6 +116,8 @@ public:
     explicit CodeSnipFragment(const QString &code) : m_code(code) {}
     explicit CodeSnipFragment(const TemplateInstancePtr &instance) : m_instance(instance) {}
 
+    bool isEmpty() const { return m_code.isEmpty() && m_instance.isNull(); }
+
     QString code() const;
 
     TemplateInstancePtr instance() const { return m_instance; }
@@ -138,6 +140,9 @@ public:
         codeList.append(CodeSnipFragment(ti));
     }
 
+    bool isEmpty() const { return codeList.isEmpty(); }
+    void purgeEmptyFragments();
+
     QList<CodeSnipFragment> codeList;
 
     static QRegularExpression placeHolderRegex(int index);
@@ -167,6 +172,10 @@ public:
     TypeSystem::CodeSnipPosition position = TypeSystem::CodeSnipPositionAny;
 };
 
+/// Purge empty fragments and snippets caused by new line characters in
+/// conjunction with <insert-template>.
+void purgeEmptyCodeSnips(QList<CodeSnip> *list);
+
 class ArgumentModification
 {
 public:
diff --git a/sources/shiboken6/ApiExtractor/typesystemparser.cpp b/sources/shiboken6/ApiExtractor/typesystemparser.cpp
index 2253b2350..684800719 100644
--- a/sources/shiboken6/ApiExtractor/typesystemparser.cpp
+++ b/sources/shiboken6/ApiExtractor/typesystemparser.cpp
@@ -846,6 +846,7 @@ bool TypeSystemParser::endElement(StackElement element)
                     toNative->setSourceType(m_database->findType(toNative->sourceTypeName()));
             }
         }
+        purgeEmptyCodeSnips(&top->entry->codeSnips());
         break;
     case StackElement::FunctionTypeEntry:
         TypeDatabase::instance()->addGlobalUserFunctionModifications(top->functionMods);
@@ -858,6 +859,7 @@ bool TypeSystemParser::endElement(StackElement element)
         Q_ASSERT(top->entry);
         Q_ASSERT(top->entry->isComplex());
         auto *centry = static_cast<ComplexTypeEntry *>(top->entry);
+        purgeEmptyCodeSnips(&centry->codeSnips());
         centry->setAddedFunctions(top->addedFunctions);
         centry->setFunctionModifications(top->functionMods);
         centry->setFieldModifications(top->fieldMods);
@@ -939,6 +941,11 @@ bool TypeSystemParser::endElement(StackElement element)
             snip->addTemplateInstance(m_templateInstance);
         m_templateInstance.reset();
         break;
+
+    case StackElement::ModifyArgument:
+        purgeEmptyCodeSnips(&top->functionMods.last().argument_mods().last().conversionRules());
+        break;
+
     default:
         break;
     }