Prevent accidentally recursing forever in VSIMkdirRecursive

Also moves the existence test up to try to avoid recursion if possible

Patch by Pete Klier at Google


git-svn-id: https://svn.osgeo.org/gdal/trunk@41195 f0d54148-0727-0410-94bb-9a71ac55c965

gdal/port/cpl_vsil.cpp

@@ -361,19 +361,28 @@ int VSIMkdirRecursive( const char *pszPathname, long mode )
         return -1;
     }
 
-    VSIStatBufL sStat;
     const CPLString osPathname(pszPathname);
+    VSIStatBufL sStat;
+    if( VSIStatL(osPathname, &sStat) == 0 &&
+        VSI_ISDIR(sStat.st_mode) )
+    {
+        return 0;
+    }
     const CPLString osParentPath(CPLGetPath(osPathname));
+
+    // Prevent crazy paths from recursing forever.
+    if( osParentPath == osPathname ||
+        osParentPath.length() >= osPathname.length() )
+    {
+        return -1;
+    }
+
     if( VSIStatL(osParentPath, &sStat) != 0 )
     {
         if( VSIMkdirRecursive(osParentPath, mode) != 0 )
             return -1;
     }
-    if( VSIStatL(osPathname, &sStat) == 0 &&
-        VSI_ISDIR(sStat.st_mode) )
-    {
-        return 0;
-    }
+
     return VSIMkdir(osPathname, mode);
 }