Add "symlink" option for "bin-compat" config (#9959)

doc/06-config.md

@@ -253,11 +253,12 @@ Defaults to `false`. Whether to use the Composer cache in read-only mode.
 ## bin-compat
 
 Defaults to `auto`. Determines the compatibility of the binaries to be installed.
-If it is `auto` then Composer only installs .bat proxy files when on Windows. If
+If it is `auto` then Composer only installs .bat proxy files when on Windows or WSL. If
 set to `full` then both .bat files for Windows and scripts for Unix-based
 operating systems will be installed for each binary. This is mainly useful if you
-run Composer inside a linux VM but still want the .bat proxies available for use
-in the Windows host OS.
+run Composer inside a linux VM but still want the `.bat` proxies available for use
+in the Windows host OS. If set to `symlink` Composer will always symlink even on 
+Windows/WSL.
 
 ## prepend-autoloader
 

res/composer-schema.json

@@ -251,8 +251,8 @@
                     "description": "Whether to use the Composer cache in read-only mode."
                 },
                 "bin-compat": {
-                    "enum": ["auto", "full"],
-                    "description": "The compatibility of the binaries, defaults to \"auto\" (automatically guessed) and can be \"full\" (compatible with both Windows and Unix-based systems)."
+                    "enum": ["auto", "full", "symlink"],
+                    "description": "The compatibility of the binaries, defaults to \"auto\" (automatically guessed), can be \"full\" (compatible with both Windows and Unix-based systems) and \"symlink\" (symlink also for WSL)."
                 },
                 "discard-changes": {
                     "type": ["string", "boolean"],

src/Composer/Command/ConfigCommand.php

@@ -390,7 +390,7 @@ EOT
             ),
             'bin-compat' => array(
                 function ($val) {
-                    return in_array($val, array('auto', 'full'));
+                    return in_array($val, array('auto', 'full', 'symlink'));
                 },
                 function ($val) {
                     return $val;

src/Composer/Installer/BinaryInstaller.php

@@ -92,6 +92,8 @@ class BinaryInstaller
                 }
             } elseif ($this->binCompat === "full") {
                 $this->installFullBinaries($binPath, $link, $bin, $package);
+            } elseif ($this->binCompat === "symlink") {
+                $this->installSymlinkBinaries($binPath, $link);
             }
             Silencer::call('chmod', $link, 0777 & ~umask());
         }