fix: dicts and list need _holderify for fallback

mesonbuild/interpreterbase/interpreterbase.py

@@ -799,7 +799,7 @@ The result of this is undefined and will become a hard error in a future Meson r
             index = posargs[0]
             fallback = None
             if len(posargs) == 2:
-                fallback = posargs[1]
+                fallback = self._holderify(posargs[1])
             elif len(posargs) > 2:
                 m = 'Array method \'get()\' only takes two arguments: the ' \
                     'index and an optional fallback value if the index is ' \
@@ -845,7 +845,7 @@ The result of this is undefined and will become a hard error in a future Meson r
                 return obj[key]
 
             if len(posargs) == 2:
-                fallback = posargs[1]
+                fallback = self._holderify(posargs[1])
                 if isinstance(fallback, mparser.BaseNode):
                     return self.evaluate_statement(fallback)
                 return fallback

test cases/common/242 set and get variable/meson.build

@@ -1,7 +1,7 @@
 project('set and get')
 
 var1 = 'test1.txt'
-var2 = files('test1.txt')
+var2 = files('test1.txt')[0]
 
 # Use is_disabler for accessing variables
 assert(var1 == 'test1.txt')
@@ -9,7 +9,7 @@ assert(not is_disabler(var2))
 
 # Ensure that set variables behave correctly
 set_variable('var3', 'test2.txt')
-set_variable('var4', files('test2.txt'))
+set_variable('var4', files('test2.txt')[0])
 
 assert(var3 == 'test2.txt')
 assert(not is_disabler(var4))
@@ -35,3 +35,29 @@ assert(var7 == 'test2.txt')
 assert(not is_disabler(var8))
 assert(get_variable('var9') == 'test2.txt')
 assert(not is_disabler(get_variable('var0')))
+
+# test dict get
+dict = {'a': var2}
+
+dict_t1 = dict['a']
+dict_t2 = dict.get('a')
+dict_t3 = dict.get('a', var2)
+dict_t4 = dict.get('b', var2)
+
+assert(not is_disabler(dict_t1))
+assert(not is_disabler(dict_t2))
+assert(not is_disabler(dict_t3))
+assert(not is_disabler(dict_t4))
+
+# test lists
+list = [var2]
+
+list_t1 = list[0]
+list_t2 = list.get(0)
+list_t3 = list.get(0, var2)
+list_t4 = list.get(1, var2)
+
+assert(not is_disabler(list_t1))
+assert(not is_disabler(list_t2))
+assert(not is_disabler(list_t3))
+assert(not is_disabler(list_t4))