On composer install we fix locked packages, but consider them locked for error reporting

src/Composer/DependencyResolver/Request.php

@@ -45,6 +45,7 @@ class Request
     protected $requires = array();
     protected $fixedPackages = array();
     protected $lockedPackages = array();
+    protected $fixedLockedPackages = array();
     protected $updateAllowList = array();
     protected $updateAllowTransitiveDependencies = false;
 
@@ -84,6 +85,15 @@ class Request
         $this->lockedPackages[spl_object_hash($package)] = $package;
     }
 
+    /**
+     * Mark a package fixed, but also keep track it is from the lock file (needed for composer install error reporting)
+     */
+    public function fixLockedPackage(PackageInterface $package)
+    {
+        $this->fixedPackages[spl_object_hash($package)] = $package;
+        $this->fixedLockedPackages[spl_object_hash($package)] = $package;
+    }
+
     public function unlockPackage(PackageInterface $package)
     {
         unset($this->lockedPackages[spl_object_hash($package)]);
@@ -132,7 +142,7 @@ class Request
 
     public function isLockedPackage(PackageInterface $package)
     {
-        return isset($this->lockedPackages[spl_object_hash($package)]);
+        return isset($this->lockedPackages[spl_object_hash($package)]) || isset($this->fixedLockedPackages[spl_object_hash($package)]);
     }
 
     public function getFixedOrLockedPackages()

src/Composer/DependencyResolver/Rule.php

@@ -199,6 +199,10 @@ abstract class Rule
             case self::RULE_FIXED:
                 $package = $this->deduplicateDefaultBranchAlias($this->reasonData['package']);
 
+                if ($request->isLockedPackage($package)) {
+                    return $package->getPrettyName().' is locked to version '.$package->getPrettyVersion().' and an update of this package was not requested.';
+                }
+
                 return $package->getPrettyName().' is present at version '.$package->getPrettyVersion() . ' and cannot be modified by Composer';
 
             case self::RULE_PACKAGE_CONFLICT:

src/Composer/Installer.php

@@ -633,7 +633,7 @@ class Installer
             }
 
             foreach ($lockedRepository->getPackages() as $package) {
-                $request->fixPackage($package);
+                $request->fixLockedPackage($package);
             }
 
             foreach ($this->locker->getPlatformRequirements($this->devMode) as $link) {
@@ -651,7 +651,6 @@ class Installer
                 // installing the locked packages on this platform resulted in lock modifying operations, there wasn't a conflict, but the lock file as-is seems to not work on this system
                 if (0 !== count($lockTransaction->getOperations())) {
                     $this->io->writeError('<error>Your lock file cannot be installed on this system without changes. Please run composer update.</error>', true, IOInterface::QUIET);
-                    // TODO actually display operations to explain what happened?
                     return 1;
                 }
             } catch (SolverProblemsException $e) {

tests/Composer/Test/Fixtures/installer/partial-update-from-lock.test

@@ -21,7 +21,8 @@ Partial update from lock file should update everything to the state of the lock,
     "require": {
         "a/old": "*",
         "b/unstable": "*",
-        "c/uptodate": "*"
+        "c/uptodate": "*",
+        "e/newreq": "*"
     }
 }
 --LOCK--
@@ -60,7 +61,6 @@ update b/unstable
         { "name": "a/old", "version": "1.0.0", "type": "library" },
         { "name": "b/unstable", "version": "1.0.0", "type": "library", "require": {"f/dependency": "1.*"} },
         { "name": "c/uptodate", "version": "1.0.0", "type": "library" },
-        { "name": "d/removed", "version": "1.0.0", "type": "library" },
         { "name": "e/newreq", "version": "1.0.0", "type": "library" },
         { "name": "f/dependency", "version": "1.0.0", "type": "library" }
     ],
@@ -77,5 +77,4 @@ update b/unstable
 Upgrading a/old (0.9.0 => 1.0.0)
 Downgrading b/unstable (1.1.0-alpha => 1.0.0)
 Downgrading c/uptodate (2.0.0 => 1.0.0)
-Installing d/removed (1.0.0)
 Installing e/newreq (1.0.0)

tests/Composer/Test/Fixtures/installer/root-alias-change-with-circular-dep.test

@@ -62,6 +62,4 @@ Your lock file does not contain a compatible set of packages. Please run compose
     - b/requirer is locked to version 1.0.0 and an update of this package was not requested.
     - b/requirer 1.0.0 requires root/pkg ^1 -> found root/pkg[2.x-dev] but it does not match the constraint.
 
-Use the option --with-all-dependencies to allow upgrades, downgrades and removals for packages currently locked to specific versions.
-
 --EXPECT--