prevent disabler() object from overwriting arrays (#7484)

* prevent disabler object from overwriting arrays

fixes #7107

* fix failing test

forgot that func() != func(void) in c

mesonbuild/interpreterbase.py

@@ -810,9 +810,7 @@ The result of this is undefined and will become a hard error in a future Meson r
         assert(isinstance(node, mparser.PlusAssignmentNode))
         varname = node.var_name
         addition = self.evaluate_statement(node.value)
-        if is_disabler(addition):
+
-            self.set_variable(varname, addition)
-            return
         # Remember that all variables are immutable. We must always create a
         # full new variable and then assign it.
         old_variable = self.get_variable(varname)

test cases/common/235 disabler array addition/meson.build

@@ -0,0 +1,9 @@
+project('disabler_inside_array', 'c')
+
+exes = []
+
+exes += library('a', 'test.c')
+
+exes += library('b', 'test.c', dependencies : disabler())
+
+exes += library('c', 'test.c')

test cases/common/235 disabler array addition/test.c

@@ -0,0 +1 @@
+int stub(void) { return 0; }