Installed packages are now always removed unless otherwise requested

This means that an update request must always be accompanied by an install
request, otherwise the package might be removed rather than updated.

src/Composer/DependencyResolver/Solver.php

@@ -730,14 +730,12 @@ class Solver
             }
         }
 
-        // solver_addrpmrulesforweak(solv, &addedmap);
-
         foreach ($this->installedMap as $package) {
             $updates = $this->policy->findUpdatePackages($this, $this->pool, $this->installedMap, $package);
             $rule = $this->createUpdateRule($package, $updates, Rule::RULE_INTERNAL_ALLOW_UPDATE, (string) $package);
 
             $rule->setWeak(true);
-            $this->addRule(RuleSet::TYPE_FEATURE, $rule);
+            //$this->addRule(RuleSet::TYPE_FEATURE, $rule);
             $this->packageToFeatureRule[$package->getId()] = $rule;
         }
 
@@ -857,6 +855,18 @@ class Solver
             }
         }
 
+        foreach ($this->decisionMap as $packageId => $decision) {
+            if ($packageId === 0) {
+                continue;
+            }
+
+            if (0 == $decision && isset($this->installedMap[$packageId])) {
+                $transaction[] = new Operation\UninstallOperation(
+                    $this->pool->packageById($packageId), null
+                );
+            }
+        }
+
         return array_reverse($transaction);
     }
 
@@ -1546,125 +1556,6 @@ class Solver
                 }
             }
 
-            // handle installed packages
-            if ($level < $systemLevel) {
-                // use two passes if any packages are being updated
-                // -> better user experience
-                for ($pass = (count($this->updateMap)) ? 0 : 1; $pass < 2; $pass++) {
-                    $passLevel = $level;
-                    for ($i = $installedPos, $n = 0; $n < count($this->installedPackages); $i++, $n++) {
-                        $repeat = false;
-
-                        if ($i == count($this->installedPackages)) {
-                            $i = 0;
-                        }
-                        $literal = new Literal($this->installedPackages[$i], true);
-
-                        if ($this->decisionsContain($literal)) {
-                            continue;
-                        }
-
-                        // only process updates in first pass
-                        /** TODO: && or || ? **/
-                        if (0 === $pass && !isset($this->updateMap[$literal->getPackageId()])) {
-                            continue;
-                        }
-
-                        $rule = null;
-
-                        if (isset($this->packageToFeatureRule[$literal->getPackageId()])) {
-                            $rule = $this->packageToFeatureRule[$literal->getPackageId()];
-                        }
-
-                        if (!$rule || $rule->isDisabled()) {
-                            continue;
-                        }
-
-                        $updateRuleLiterals = $rule->getLiterals();
-
-                        $decisionQueue = array();
-                        if (!isset($this->noUpdate[$literal->getPackageId()]) && (
-                            $this->decidedRemove($literal->getPackage()) ||
-                            isset($this->updateMap[$literal->getPackageId()]) ||
-                            !$literal->equals($updateRuleLiterals[0])
-                        )) {
-                            foreach ($updateRuleLiterals as $ruleLiteral) {
-                                if ($this->decidedInstall($ruleLiteral->getPackage())) {
-                                    // already fulfilled
-                                    $decisionQueue = array();
-                                    break;
-                                }
-                                if ($this->undecided($ruleLiteral->getPackage())) {
-                                    $decisionQueue[] = $ruleLiteral;
-                                }
-                            }
-                        }
-
-                        if (sizeof($decisionQueue)) {
-                            $oLevel = $level;
-                            $level = $this->selectAndInstall($level, $decisionQueue, $disableRules, $rule);
-
-                            if (0 === $level) {
-                                return;
-                            }
-
-                            if ($level <= $oLevel) {
-                                $repeat = true;
-                            }
-                        } else if (!$repeat && $this->undecided($literal->getPackage())) {
-                            // still undecided? keep package.
-                            $oLevel = $level;
-                            if (isset($this->cleanDepsMap[$literal->getPackageId()])) {
-                                // clean deps removes package
-                                $level = $this->setPropagateLearn($level, $literal->invert(), $disableRules, null);
-                            } else {
-                                // ckeeping package
-                                $level = $this->setPropagateLearn($level, $literal, $disableRules, $rule);
-                            }
-
-
-                            if (0 === $level) {
-                                return;
-                            }
-
-                            if ($level <= $oLevel) {
-                                $repeat = true;
-                            }
-                        }
-
-                        if ($repeat) {
-                            if (1 === $level || $level < $passLevel) {
-                                // trouble
-                                break;
-                            }
-                            if ($level < $oLevel) {
-                                // redo all
-                                $n = 0;
-                            }
-
-                            // repeat
-                            $i--;
-                            $n--;
-                            continue;
-                        }
-                    }
-
-                    if ($n < count($this->installedPackages)) {
-                        $installedPos = $i; // retry this problem next time
-                        break;
-                    }
-
-                    $installedPos = 0;
-                }
-
-                $systemLevel = $level + 1;
-
-                if ($pass < 2) {
-                    // had trouble => retry
-                    continue;
-                }
-            }
-
             if ($level < $systemLevel) {
                 $systemLevel = $level;
             }

tests/Composer/Test/DependencyResolver/SolverTest.php

@@ -54,6 +54,16 @@ class SolverTest extends TestCase
         ));
     }
 
+    public function testSolverRemoveIfNotInstalled()
+    {
+        $this->repoInstalled->addPackage($packageA = $this->getPackage('A', '1.0'));
+        $this->reposComplete();
+
+        $this->checkSolverResult(array(
+            array('job' => 'remove', 'package' => $packageA),
+        ));
+    }
+
     public function testInstallNonExistingPackageFails()
     {
         $this->repo->addPackage($this->getPackage('A', '1.0'));
@@ -176,6 +186,7 @@ class SolverTest extends TestCase
         $this->repo->addPackage($newPackageA = $this->getPackage('A', '1.1'));
         $this->reposComplete();
 
+        $this->request->install('A');
         $this->request->update('A');
 
         $this->checkSolverResult(array(
@@ -191,6 +202,7 @@ class SolverTest extends TestCase
         $this->repo->addPackage($newPackageB = $this->getPackage('B', '1.1'));
 
         $packageA->setRequires(array(new Link('A', 'B', null, 'requires')));
+        $newPackageA->setRequires(array(new Link('A', 'B', null, 'requires')));
 
         $this->reposComplete();
 
@@ -209,6 +221,7 @@ class SolverTest extends TestCase
         $this->repo->addPackage($this->getPackage('A', '1.0'));
         $this->reposComplete();
 
+        $this->request->install('A');
         $this->request->update('A');
 
         $this->checkSolverResult(array());
@@ -223,6 +236,8 @@ class SolverTest extends TestCase
 
         $this->reposComplete();
 
+        $this->request->install('A');
+        $this->request->install('B');
         $this->request->update('A');
 
         $this->checkSolverResult(array(
@@ -267,7 +282,7 @@ class SolverTest extends TestCase
     public function testSolverUpdateFullyConstrainedPrunesInstalledPackages()
     {
         $this->repoInstalled->addPackage($packageA = $this->getPackage('A', '1.0'));
-        $this->repoInstalled->addPackage($this->getPackage('B', '1.0'));
+        $this->repoInstalled->addPackage($packageB = $this->getPackage('B', '1.0'));
         $this->repo->addPackage($newPackageA = $this->getPackage('A', '1.2'));
         $this->repo->addPackage($this->getPackage('A', '2.0'));
         $this->reposComplete();
@@ -275,7 +290,12 @@ class SolverTest extends TestCase
         $this->request->install('A', $this->getVersionConstraint('<', '2.0.0.0'));
         $this->request->update('A', $this->getVersionConstraint('=', '1.0.0.0'));
 
-        $this->checkSolverResult(array(array(
+        $this->checkSolverResult(array(
+            array(
+                'job' => 'remove',
+                'package' => $packageB,
+            ),
+            array(
                 'job' => 'update',
                 'from' => $packageA,
                 'to' => $newPackageA,
@@ -297,6 +317,7 @@ class SolverTest extends TestCase
         $this->reposComplete();
 
         $this->request->install('A');
+        $this->request->install('C');
         $this->request->update('C');
         $this->request->remove('D');