Solver: Move analyze handling of multiconflict rule to clearer location

This way we're not looking at the previous decision at the top of the
loop but working with the current decision at the bottom

src/Composer/DependencyResolver/Solver.php

@@ -417,18 +417,6 @@ class Solver
             }
             unset($literal);
 
-            if ($decisionId > 0) {
-                $decision = $this->decisions->atOffset($decisionId-1);
-                if ($rule !== $decision[Decisions::DECISION_REASON] && $decision[Decisions::DECISION_REASON] instanceof MultiConflictRule) {
-                    $num++;
-                    foreach ($decision[Decisions::DECISION_REASON]->getLiterals() as $literal) {
-                        if (!$this->decisions->satisfy($literal)) {
-                            $seen[abs($literal)] = true;
-                        }
-                    }
-                }
-            }
-
             $l1retry = true;
             while ($l1retry) {
                 $l1retry = false;
@@ -481,6 +469,15 @@ class Solver
                 $rule = $decision[Decisions::DECISION_REASON];
 
                 if ($rule instanceof MultiConflictRule) {
+                    // there is only ever exactly one positive decision in a multiconflict rule
+                    foreach ($rule->getLiterals() as $literal) {
+                        if (!isset($seen[abs($literal)]) && !$this->decisions->satisfy($literal)) {
+                            $num++;
+                            $seen[abs($literal)] = true;
+                            break;
+                        }
+                    }
+
                     $l1retry = true;
                 }
             }