fixed ABI incompatibilities as proposed by alalek

related to issue 4969
fixes issue 5891
fixes issue 5922

modules/ml/include/opencv2/ml.hpp

@@ -720,9 +720,14 @@ public:
     find the best parameters for your problem, it can be done with SVM::trainAuto. */
     CV_WRAP static Ptr<SVM> create();
 
-    CV_WRAP virtual void read( const FileNode& fn ) = 0;
+    /** @brief Loads and creates a serialized svm from a file
-
+     *
-    CV_WRAP static Ptr<SVM> load(const String& fs);
+     * Use SVM::save to serialize and store an SVM to disk.
+     * Load the SVM from this file again, by calling this function with the path to the file.
+     *
+     * @param fs Filename
+     */
+    CV_WRAP static Ptr<SVM> load(const String& filepath);
 };
 
 /****************************************************************************************\

modules/ml/src/svm.cpp

@@ -2261,14 +2261,14 @@ Ptr<SVM> SVM::create()
     return makePtr<SVMImpl>();
 }
 
-Ptr<SVM> SVM::load(const String& filename)
+Ptr<SVM> SVM::load(const String& filepath)
 {
     FileStorage fs;
-    fs.open(filename, FileStorage::READ);
+    fs.open(filepath, FileStorage::READ);
 
     Ptr<SVM> svm = makePtr<SVMImpl>();
 
-    svm->read(fs.getFirstTopLevelNode());
+    ((SVMImpl*)svm.get())->read(fs.getFirstTopLevelNode());
     return svm;
 }