Set a 50-character limit on the saved size of option section and name.

Allows use of istream::getline() to retrieve the values, simplifying
delimiter detection.

libgnucash/app-utils/gnc-option.hpp

@@ -119,6 +119,9 @@ enum GncOptionUIType
 
 static const char* commodity_scm_intro{"'(commodity-scm "};
 
+size_t constexpr classifier_size_max{50};
+size_t constexpr sort_tag_size_max{10};
+
 struct OptionClassifier
 {
     std::string m_section;

libgnucash/app-utils/gnc-optiondb.cpp

@@ -124,13 +124,13 @@ GncOptionDB::set_option_from_ui(const char* section, const char* name,
 
 
 std::optional<std::reference_wrapper<GncOptionSection>>
-GncOptionDB::find_section(const char* section)
+GncOptionDB::find_section(const std::string& section)
 {
     auto db_section = std::find_if(
         m_sections.begin(), m_sections.end(),
-        [section](GncOptionSection sect) -> bool
+        [&section](GncOptionSection sect) -> bool
         {
-            return sect.first == std::string{section};
+            return section.compare(0, classifier_size_max, sect.first) == 0;
         });
     if (db_section == m_sections.end())
         return std::nullopt;
@@ -138,16 +138,17 @@ GncOptionDB::find_section(const char* section)
 }
 
 std::optional<std::reference_wrapper<GncOption>>
-GncOptionDB::find_option(const char* section, const char* name) const
+GncOptionDB::find_option(const std::string& section, const std::string& name) const
 {
     auto db_section = const_cast<GncOptionDB*>(this)->find_section(section);
     if (!db_section)
         return std::nullopt;
     auto db_opt = std::find_if(
         db_section->get().second.begin(), db_section->get().second.end(),
-        [name](GncOption& option) -> bool
+        [&name](GncOption& option) -> bool
         {
-            return option.get_name() == std::string{name};
+            return name.compare(0, classifier_size_max - 1,
+                                  option.get_name()) == 0;
         });
     if (db_opt == db_section->get().second.end())
         return std::nullopt;

libgnucash/app-utils/gnc-optiondb.hpp

@@ -83,13 +83,13 @@ public:
 //    void set_selectable(const char* section, const char* name);
     void make_internal(const char* section, const char* name);
     void commit();
-    std::optional<std::reference_wrapper<GncOptionSection>> find_section(const char* section);
-    std::optional<std::reference_wrapper<GncOption>> find_option(const char* section, const char* name) {
+    std::optional<std::reference_wrapper<GncOptionSection>> find_section(const std::string& section);
+    std::optional<std::reference_wrapper<GncOption>> find_option(const std::string& section, const std::string& name) {
         return static_cast<const GncOptionDB&>(*this).find_option(section, name);
     }
-    std::optional<std::reference_wrapper<GncOption>> find_option(const char* section, const char* name) const;
 private:
     std::ostream& serialize_option_scheme(std::ostream& oss,
+    std::optional<std::reference_wrapper<GncOption>> find_option(const std::string& section, const std::string& name) const;
                                           const char* option_prolog,
                                           const char* section, const char* name) const noexcept;
     std::ostream& serialize_option_key_value(std::ostream& oss,