[template-glib] scope: add dup_string() helper

[Christian Hergert <chergert src gnome org>]

commit d5493a5611c3823903e78ac706fafb5d876d5ae6
Author: Christian Hergert <chergert redhat com>
Date:   Fri May 27 17:48:55 2022 -0700

    scope: add dup_string() helper

 src/tmpl-scope.c | 31 +++++++++++++++++++++++++++++++
 src/tmpl-scope.h |  3 +++
 2 files changed, 34 insertions(+)
---
diff --git a/src/tmpl-scope.c b/src/tmpl-scope.c
index b61a088..81d1cf6 100644
--- a/src/tmpl-scope.c
+++ b/src/tmpl-scope.c
@@ -493,3 +493,34 @@ tmpl_scope_set_null (TmplScope  *self,
 
   tmpl_scope_set_value (self, name, &value);
 }
+
+/**
+ * tmpl_scope_dup_string:
+ * @self: a #TmplScope
+ *
+ * Gets a string if the symbol @name is a string.
+ *
+ * Otherwise, %NULL is returned.
+ *
+ * Returns: (transfer full) (nullable): a string or %NULL
+ *
+ * Since: 3.36
+ */
+char *
+tmpl_scope_dup_string (TmplScope  *self,
+                       const char *name)
+{
+  GValue value = G_VALUE_INIT;
+  TmplSymbol *symbol;
+  char *ret = NULL;
+
+  if (!(symbol = tmpl_scope_peek (self, name)))
+    return NULL;
+
+  tmpl_symbol_get_value (symbol, &value);
+  if (G_VALUE_HOLDS_STRING (&value))
+    ret = g_value_dup_string (&value);
+  g_value_unset (&value);
+
+  return ret;
+}
diff --git a/src/tmpl-scope.h b/src/tmpl-scope.h
index 8e09c9c..8965a9a 100644
--- a/src/tmpl-scope.h
+++ b/src/tmpl-scope.h
@@ -102,6 +102,9 @@ char      **tmpl_scope_list_symbols    (TmplScope         *self,
 TMPL_AVAILABLE_IN_3_36
 void        tmpl_scope_set_null        (TmplScope         *self,
                                         const char        *name);
+TMPL_AVAILABLE_IN_3_36
+char       *tmpl_scope_dup_string      (TmplScope         *self,
+                                        const char        *name);
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (TmplScope, tmpl_scope_unref)