From: "Erich E. Hoover" <erich.e.hoover@gmail.com>
Subject: [PATCH 5/8] kernel32: Handle bogus DOS paths in GetVolumePathName.
Message-Id: <CAEU2+vqzM_V9b7HEvM+bk8v=0ocVEUDMPWTHAQi9N=wfbmrwtA@mail.gmail.com>
Date: Thu, 18 Jun 2015 19:16:47 -0600

Paths that are not NT and not even close to DOS don't actually fail
catastrophically.  Even though MSDN suggests that it returns the boot
drive in this case, my tests on the testbot indicate that it returns
the drive of the current working directory.

From f988a64b010748972d38af5cb0fa15dbacc14b7d Mon Sep 17 00:00:00 2001
From: "Erich E. Hoover" <erich.e.hoover@wine-staging.com>
Date: Mon, 15 Jun 2015 22:20:03 -0600
Subject: kernel32: Handle bogus DOS paths in GetVolumePathName.

---
 dlls/kernel32/tests/volume.c | 22 ++++++++++++++++++----
 dlls/kernel32/volume.c       | 12 ++++++++++++
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/dlls/kernel32/tests/volume.c b/dlls/kernel32/tests/volume.c
index 5b117b8..7ed55d7 100644
--- a/dlls/kernel32/tests/volume.c
+++ b/dlls/kernel32/tests/volume.c
@@ -591,7 +591,7 @@ static void test_disk_extents(void)
 
 static void test_GetVolumePathNameA(void)
 {
-    char volume_path[MAX_PATH];
+    char volume_path[MAX_PATH], cwd[MAX_PATH];
     struct {
         const char *file_name;
         const char *path_name;
@@ -671,6 +671,10 @@ static void test_GetVolumePathNameA(void)
             "M::", "C:\\", 4,
             ERROR_FILE_NOT_FOUND, ERROR_MORE_DATA
         },
+        { /* test 17: an unreasonable DOS path */
+            "InvalidDrive:\\AnInvalidFolder", "%CurrentDrive%\\", sizeof(volume_path),
+            NO_ERROR, NO_ERROR
+        },
     };
     BOOL ret, success;
     DWORD error;
@@ -683,6 +687,13 @@ static void test_GetVolumePathNameA(void)
         return;
     }
 
+    /* Obtain the drive of the working directory */
+    ret = GetCurrentDirectoryA( sizeof(cwd), cwd );
+    ok( ret, "Failed to obtain the current working directory.\n" );
+    cwd[2] = 0;
+    ret = SetEnvironmentVariableA( "CurrentDrive", cwd );
+    ok( ret, "Failed to set an environment variable for the current working drive.\n" );
+
     for (i=0; i<sizeof(test_paths)/sizeof(test_paths[0]); i++)
     {
         BOOL broken_ret = test_paths[i].broken_error == NO_ERROR ? TRUE : FALSE;
@@ -699,11 +710,14 @@ static void test_GetVolumePathNameA(void)
 
         if (ret)
         {
+            char path_name[MAX_PATH];
+
+            ExpandEnvironmentStringsA( test_paths[i].path_name, path_name, MAX_PATH);
             /* If we succeeded then make sure the path is correct */
-            success = (strcmp( volume_path, test_paths[i].path_name ) == 0)
-                      || broken(strcasecmp( volume_path, test_paths[i].path_name ) == 0) /* XP */;
+            success = (strcmp( volume_path, path_name ) == 0)
+                      || broken(strcasecmp( volume_path, path_name ) == 0) /* XP */;
             ok(success, "GetVolumePathName test %d unexpectedly returned path %s (expected %s).\n",
-                        i, volume_path, test_paths[i].path_name);
+                        i, volume_path, path_name);
         }
         else
         {
diff --git a/dlls/kernel32/volume.c b/dlls/kernel32/volume.c
index 3eef540..e135967 100644
--- a/dlls/kernel32/volume.c
+++ b/dlls/kernel32/volume.c
@@ -1889,6 +1889,8 @@ BOOL WINAPI GetVolumePathNameW(LPCWSTR filename, LPWSTR volumepathname, DWORD bu
 
     if (status != STATUS_SUCCESS)
     {
+        WCHAR cwdW[MAX_PATH];
+
         /* the path was completely invalid */
         if (filename[0] == '\\')
         {
@@ -1908,6 +1910,16 @@ BOOL WINAPI GetVolumePathNameW(LPCWSTR filename, LPWSTR volumepathname, DWORD bu
                 goto cleanup;
             }
         }
+        else if (GetCurrentDirectoryW( sizeof(cwdW), cwdW ))
+        {
+            /* if the path is completely bogus then revert to the drive of the working directory */
+            fallbackpathW[0] = cwdW[0];
+        }
+        else
+        {
+            status = STATUS_OBJECT_NAME_INVALID;
+            goto cleanup;
+        }
         last_pos = strlenW(fallbackpathW) - 1; /* points to \\ */
         filename = fallbackpathW;
         status = STATUS_SUCCESS;

-- 
1.9.1