Fixed #6885 (valueflow ignores assignment of variable via function call)

lib/valueflow.cpp

@@ -1381,8 +1381,10 @@ static bool valueFlowForward(Token * const               startToken,
             }
             if (inconclusive) {
                 std::list<ValueFlow::Value>::iterator it;
-                for (it = values.begin(); it != values.end(); ++it)
+                for (it = values.begin(); it != values.end(); ++it) {
                     it->inconclusive = true;
+                    it->changeKnownToPossible();
+                }
             }
         }
 

test/testvalueflow.cpp

@@ -1618,6 +1618,13 @@ private:
         ASSERT_EQUALS(9, value.intvalue);
         ASSERT(value.isPossible());
 
+        code = "void f() {\n"
+               "  int x = 0;\n"
+               "  fred.dostuff(x);\n"
+               "  if (x < 0) {}\n"
+               "}\n";
+        ASSERT(isNotKnownValues(code, "<"));
+
         code = "void f() {\n"
                "  int x = 0;\n"
                "  if (y) { dostuff(x); }\n"