Merge pull request #12391 from DEEPIR:master

fix some errors found by static analyzer. (#12391)

* fix possible divided by zero and by negative values

* only 4 elements are used in these arrays

* fix uninitialized member

* use boolean type for semantic boolean variables

* avoid invalid array index

* to avoid exception and because base64_beg is only used in this block

* use std::atomic<bool> to avoid thread control race condition

modules/core/src/matrix_wrap.cpp

@@ -939,7 +939,7 @@ bool _InputArray::isContinuous(int i) const
     if( k == STD_VECTOR_MAT )
     {
         const std::vector<Mat>& vv = *(const std::vector<Mat>*)obj;
-        CV_Assert((size_t)i < vv.size());
+        CV_Assert(i >= 0 && (size_t)i < vv.size());
         return vv[i].isContinuous();
     }
 
@@ -953,7 +953,7 @@ bool _InputArray::isContinuous(int i) const
     if( k == STD_VECTOR_UMAT )
     {
         const std::vector<UMat>& vv = *(const std::vector<UMat>*)obj;
-        CV_Assert((size_t)i < vv.size());
+        CV_Assert(i >= 0 && (size_t)i < vv.size());
         return vv[i].isContinuous();
     }
 

modules/core/src/parallel_impl.cpp

@@ -337,7 +337,7 @@ public:
     std::atomic<int> completed_thread_count;  // number of threads completed any activities on this job
     int64 dummy2_[8];  // avoid cache-line reusing for the same atomics
 
-    volatile bool is_completed;  // std::atomic_flag ?
+    std::atomic<bool> is_completed;
 
     // TODO exception handling
 };

modules/core/src/persistence_json.cpp

@@ -238,11 +238,11 @@ static char* icvJSONParseValue( CvFileStorage* fs, char* ptr, CvFileNode* node )
                         CV_PARSE_ERROR("Invalid `dt` in Base64 header");
                 }
 
-                /* set base64_beg to beginning of base64 data */
-                base64_beg = &base64_buffer.at( base64::ENCODED_HEADER_SIZE );
 
                 if ( base64_buffer.size() > base64::ENCODED_HEADER_SIZE )
                 {
+                    /* set base64_beg to beginning of base64 data */
+                    base64_beg = &base64_buffer.at( base64::ENCODED_HEADER_SIZE );
                     if ( !base64::base64_valid( base64_beg, 0U, base64_end - base64_beg ) )
                         CV_PARSE_ERROR( "Invalid Base64 data." );
 

modules/cudaarithm/src/arithm.cpp

@@ -451,7 +451,6 @@ namespace
         Size block_size;
         Size user_block_size;
         Size dft_size;
-        int spect_len;
 
         GpuMat image_spect, templ_spect, result_spect;
         GpuMat image_block, templ_block, result_data;
@@ -484,7 +483,7 @@ namespace
         createContinuous(dft_size, CV_32F, templ_block);
         createContinuous(dft_size, CV_32F, result_data);
 
-        spect_len = dft_size.height * (dft_size.width / 2 + 1);
+        int spect_len = dft_size.height * (dft_size.width / 2 + 1);
         createContinuous(1, spect_len, CV_32FC2, image_spect);
         createContinuous(1, spect_len, CV_32FC2, templ_spect);
         createContinuous(1, spect_len, CV_32FC2, result_spect);

modules/imgcodecs/src/grfmt_jpeg2000.cpp

@@ -179,7 +179,7 @@ bool  Jpeg2KDecoder::readData( Mat& img )
 {
     Ptr<Jpeg2KDecoder> close_this(this, Jpeg2KDecoder_close);
     bool result = false;
-    int color = img.channels() > 1;
+    bool color = img.channels() > 1;
     uchar* data = img.ptr();
     size_t step = img.step;
     jas_stream_t* stream = (jas_stream_t*)m_stream;

modules/imgcodecs/src/grfmt_png.cpp

@@ -226,7 +226,7 @@ bool  PngDecoder::readData( Mat& img )
     volatile bool result = false;
     AutoBuffer<uchar*> _buffer(m_height);
     uchar** buffer = _buffer.data();
-    int color = img.channels() > 1;
+    bool color = img.channels() > 1;
 
     png_structp png_ptr = (png_structp)m_png_ptr;
     png_infop info_ptr = (png_infop)m_info_ptr;

modules/imgcodecs/src/grfmt_pxm.cpp

@@ -208,7 +208,7 @@ bool PxMDecoder::readHeader()
 
 bool PxMDecoder::readData( Mat& img )
 {
-    int color = img.channels() > 1;
+    bool color = img.channels() > 1;
     uchar* data = img.ptr();
     PaletteEntry palette[256];
     bool   result = false;
@@ -225,7 +225,7 @@ bool PxMDecoder::readData( Mat& img )
     // create LUT for converting colors
     if( bit_depth == 8 )
     {
-        CV_Assert(m_maxval < 256);
+        CV_Assert(m_maxval < 256 && m_maxval > 0);
 
         for (int i = 0; i <= m_maxval; i++)
             gray_palette[i] = (uchar)((i*255/m_maxval)^(m_bpp == 1 ? 255 : 0));

modules/imgcodecs/src/grfmt_sunras.cpp

@@ -160,7 +160,7 @@ bool  SunRasterDecoder::readHeader()
 
 bool  SunRasterDecoder::readData( Mat& img )
 {
-    int color = img.channels() > 1;
+    bool color = img.channels() > 1;
     uchar* data = img.ptr();
     size_t step = img.step;
     uchar  gray_palette[256] = {0};

modules/imgproc/src/linefit.cpp

@@ -321,7 +321,7 @@ static void fitLine2D( const Point2f * points, int count, int dist,
     void (*calc_weights) (float *, int, float *) = 0;
     void (*calc_weights_param) (float *, int, float *, float) = 0;
     int i, j, k;
-    float _line[6], _lineprev[6];
+    float _line[4], _lineprev[4];
     float rdelta = reps != 0 ? reps : 1.0f;
     float adelta = aeps != 0 ? aeps : 0.01f;
     double min_err = DBL_MAX, err = 0;