fix build warnings for GCC 15

Author: Kumataro

modules/text/src/erfilter.cpp

@@ -1891,6 +1891,7 @@ class dissimilarity {
                      N(_Num),
                      members(_members),
                      postprocessfn(NULL),
+                     distfn(NULL),
                      V(NULL)
     {
         switch (method) {

modules/text/src/ocr_hmm_decoder.cpp

@@ -208,7 +208,7 @@ class OCRHMMDecoderImpl : public OCRHMMDecoder
             vector<int> spaces_start;
             vector<int> spaces_end;
             int space_count=0;
-            int last_one_idx;
+            int last_one_idx=0;
 
             int s_init = 0, s_end=vector_w.cols;
             for (int s=0; s<vector_w.cols; s++)
@@ -456,7 +456,7 @@ class OCRHMMDecoderImpl : public OCRHMMDecoder
             vector<int> spaces_start;
             vector<int> spaces_end;
             int space_count=0;
-            int last_one_idx;
+            int last_one_idx=0;
 
             int s_init = 0, s_end=vector_w.cols;
             for (int s=0; s<vector_w.cols; s++)

modules/wechat_qrcode/src/zxing/common/bytematrix.cpp

@@ -26,14 +26,18 @@ void ByteMatrix::init(int _width, int _height) {
     }
 }
 
-ByteMatrix::ByteMatrix(int dimension) { init(dimension, dimension); }
+ByteMatrix::ByteMatrix(int dimension) : bytes(nullptr) { init(dimension, dimension); }
 
-ByteMatrix::ByteMatrix(int _width, int _height) { init(_width, _height); }
+ByteMatrix::ByteMatrix(int _width, int _height) : bytes(nullptr) { init(_width, _height); }
 
-ByteMatrix::ByteMatrix(int _width, int _height, ArrayRef<char> source) {
+ByteMatrix::ByteMatrix(int _width, int _height, ArrayRef<char> source) : bytes(nullptr) {
     init(_width, _height);
-    int size = _width * _height;
-    memcpy(&bytes[0], &source[0], size);
+
+    if( bytes != nullptr)
+    {
+        const size_t size = _width * _height;
+        memcpy(&bytes[0], &source[0], size);
+    }
 }
 
 ByteMatrix::~ByteMatrix() {