bug #32000 [Routing] fix absolute url generation when scheme is not k…

…nown (Tobion)

This PR was merged into the 3.4 branch.

Discussion
----------

[Routing] fix absolute url generation when scheme is not known

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | #25491
| License       | MIT
| Doc PR        |

This fixes two edge cases in the url generator:
1. when the context scheme is not known (empty) generating an absolute url would return an invalid url starting with `://host/path`. #25491 handled the case when the host is unknown which makes sense. but the way it was done, created this new problem.
2. non-http(s) urls do not require a host. e.g. typical `file:///path` urls. url generator is fixed to be in line with rfc3986

Commits
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8e04222 [Routing] fix absolute url generation when scheme is not known

src/Symfony/Component/Routing/Generator/UrlGenerator.php

@@ -222,16 +222,18 @@ protected function doGenerate($variables, $defaults, $requirements, $tokens, $pa
             }
         }
 
-        if ((self::ABSOLUTE_URL === $referenceType || self::NETWORK_PATH === $referenceType) && !empty($host)) {
-            $port = '';
-            if ('http' === $scheme && 80 != $this->context->getHttpPort()) {
-                $port = ':'.$this->context->getHttpPort();
-            } elseif ('https' === $scheme && 443 != $this->context->getHttpsPort()) {
-                $port = ':'.$this->context->getHttpsPort();
-            }
+        if (self::ABSOLUTE_URL === $referenceType || self::NETWORK_PATH === $referenceType) {
+            if ('' !== $host || ('' !== $scheme && 'http' !== $scheme && 'https' !== $scheme)) {
+                $port = '';
+                if ('http' === $scheme && 80 !== $this->context->getHttpPort()) {
+                    $port = ':'.$this->context->getHttpPort();
+                } elseif ('https' === $scheme && 443 !== $this->context->getHttpsPort()) {
+                    $port = ':'.$this->context->getHttpsPort();
+                }
 
-            $schemeAuthority = self::NETWORK_PATH === $referenceType ? '//' : "$scheme://";
-            $schemeAuthority .= $host.$port;
+                $schemeAuthority = self::NETWORK_PATH === $referenceType || '' === $scheme ? '//' : "$scheme://";
+                $schemeAuthority .= $host.$port;
+            }
         }
 
         if (self::RELATIVE_PATH === $referenceType) {

src/Symfony/Component/Routing/Tests/Generator/UrlGeneratorTest.php

@@ -480,28 +480,27 @@ public function testHostIsCaseInsensitive()
 
     public function testDefaultHostIsUsedWhenContextHostIsEmpty()
     {
-        $routes = $this->getRoutes('test', new Route('/route', ['domain' => 'my.fallback.host'], ['domain' => '.+'], [], '{domain}', ['http']));
+        $routes = $this->getRoutes('test', new Route('/path', ['domain' => 'my.fallback.host'], ['domain' => '.+'], [], '{domain}'));
 
         $generator = $this->getGenerator($routes);
         $generator->getContext()->setHost('');
 
-        $this->assertSame('http://my.fallback.host/app.php/route', $generator->generate('test', [], UrlGeneratorInterface::ABSOLUTE_URL));
+        $this->assertSame('http://my.fallback.host/app.php/path', $generator->generate('test', [], UrlGeneratorInterface::ABSOLUTE_URL));
     }
 
-    public function testDefaultHostIsUsedWhenContextHostIsEmptyAndSchemeIsNot()
+    public function testDefaultHostIsUsedWhenContextHostIsEmptyAndPathReferenceType()
     {
-        $routes = $this->getRoutes('test', new Route('/route', ['domain' => 'my.fallback.host'], ['domain' => '.+'], [], '{domain}', ['http', 'https']));
+        $routes = $this->getRoutes('test', new Route('/path', ['domain' => 'my.fallback.host'], ['domain' => '.+'], [], '{domain}'));
 
         $generator = $this->getGenerator($routes);
         $generator->getContext()->setHost('');
-        $generator->getContext()->setScheme('https');
 
-        $this->assertSame('https://my.fallback.host/app.php/route', $generator->generate('test', [], UrlGeneratorInterface::ABSOLUTE_URL));
+        $this->assertSame('//my.fallback.host/app.php/path', $generator->generate('test', [], UrlGeneratorInterface::ABSOLUTE_PATH));
     }
 
-    public function testAbsoluteUrlFallbackToRelativeIfHostIsEmptyAndSchemeIsNot()
+    public function testAbsoluteUrlFallbackToPathIfHostIsEmptyAndSchemeIsHttp()
     {
-        $routes = $this->getRoutes('test', new Route('/route', [], [], [], '', ['http', 'https']));
+        $routes = $this->getRoutes('test', new Route('/route'));
 
         $generator = $this->getGenerator($routes);
         $generator->getContext()->setHost('');
@@ -510,6 +509,39 @@ public function testAbsoluteUrlFallbackToRelativeIfHostIsEmptyAndSchemeIsNot()
         $this->assertSame('/app.php/route', $generator->generate('test', [], UrlGeneratorInterface::ABSOLUTE_URL));
     }
 
+    public function testAbsoluteUrlFallbackToNetworkIfSchemeIsEmptyAndHostIsNot()
+    {
+        $routes = $this->getRoutes('test', new Route('/path'));
+
+        $generator = $this->getGenerator($routes);
+        $generator->getContext()->setHost('example.com');
+        $generator->getContext()->setScheme('');
+
+        $this->assertSame('//example.com/app.php/path', $generator->generate('test', [], UrlGeneratorInterface::ABSOLUTE_URL));
+    }
+
+    public function testAbsoluteUrlFallbackToPathIfSchemeAndHostAreEmpty()
+    {
+        $routes = $this->getRoutes('test', new Route('/path'));
+
+        $generator = $this->getGenerator($routes);
+        $generator->getContext()->setHost('');
+        $generator->getContext()->setScheme('');
+
+        $this->assertSame('/app.php/path', $generator->generate('test', [], UrlGeneratorInterface::ABSOLUTE_URL));
+    }
+
+    public function testAbsoluteUrlWithNonHttpSchemeAndEmptyHost()
+    {
+        $routes = $this->getRoutes('test', new Route('/path', [], [], [], '', ['file']));
+
+        $generator = $this->getGenerator($routes);
+        $generator->getContext()->setBaseUrl('');
+        $generator->getContext()->setHost('');
+
+        $this->assertSame('file:///path', $generator->generate('test', [], UrlGeneratorInterface::ABSOLUTE_URL));
+    }
+
     public function testGenerateNetworkPath()
     {
         $routes = $this->getRoutes('test', new Route('/{name}', [], [], [], '{locale}.example.com', ['http']));