Follow up to #7946 test: add solver flag to assert path execution

src/Composer/DependencyResolver/Solver.php

@@ -57,6 +57,9 @@ class Solver
     /** @var array */
     protected $learnedWhy = array();
 
+    /** @var bool */
+    public $testFlagLearnedPositiveLiteral = false;
+
     /** @var IOInterface */
     protected $io;
 
@@ -470,6 +473,9 @@ class Solver
                 unset($seen[abs($literal)]);
 
                 if ($num && 0 === --$num) {
+                    if ($literal < 0) {
+                        $this->testFlagLearnedPositiveLiteral = true;
+                    }
                     $learnedLiterals[0] = -$literal;
 
                     if (!$l1num) {

tests/Composer/Test/DependencyResolver/SolverTest.php

@@ -891,6 +891,9 @@ class SolverTest extends TestCase
 
         $this->request->install('A');
 
+        // check correct setup for assertion later
+        $this->assertFalse($this->solver->testFlagLearnedPositiveLiteral);
+
         $this->checkSolverResult(array(
             array('job' => 'install', 'package' => $packageF1),
             array('job' => 'install', 'package' => $packageD),
@@ -900,6 +903,10 @@ class SolverTest extends TestCase
             array('job' => 'install', 'package' => $packageB),
             array('job' => 'install', 'package' => $packageA),
         ));
+
+        // verify that the code path leading to a negative literal resulting in a positive learned literal is actually
+        // executed
+        $this->assertTrue($this->solver->testFlagLearnedPositiveLiteral);
     }
 
     protected function reposComplete()