Do not reset step for single-row Mat created on user data

mshabunin · mshabunin · commit eb136ebba668 · 2017-11-17T13:15:15.000+03:00
diff --git a/modules/core/include/opencv2/core/mat.inl.hpp b/modules/core/include/opencv2/core/mat.inl.hpp
@@ -508,15 +508,15 @@ Mat::Mat(int _rows, int _cols, int _type, void* _data, size_t _step)
     }
     else
     {
-        if( rows == 1 ) _step = minstep;
         CV_DbgAssert( _step >= minstep );
 
         if (_step % esz1 != 0)
         {
             CV_Error(Error::BadStep, "Step must be a multiple of esz1");
         }
 
-        flags |= _step == minstep ? CONTINUOUS_FLAG : 0;
+        if (_step == minstep || rows == 1)
+            flags |= CONTINUOUS_FLAG;
     }
     step[0] = _step;
     step[1] = esz;
@@ -541,15 +541,15 @@ Mat::Mat(Size _sz, int _type, void* _data, size_t _step)
     }
     else
     {
-        if( rows == 1 ) _step = minstep;
         CV_DbgAssert( _step >= minstep );
 
         if (_step % esz1 != 0)
         {
             CV_Error(Error::BadStep, "Step must be a multiple of esz1");
         }
 
-        flags |= _step == minstep ? CONTINUOUS_FLAG : 0;
+        if (_step == minstep || rows == 1)
+            flags |= CONTINUOUS_FLAG;
     }
     step[0] = _step;
     step[1] = esz;

Original file line number	Diff line number	Diff line change
`@@ -508,15 +508,15 @@ Mat::Mat(int _rows, int _cols, int _type, void* _data, size_t _step)`
`508`	`508`	`}`
`509`	`509`	`else`
`510`	`510`	`{`
`511`		`- if( rows == 1 ) _step = minstep;`
`512`	`511`	`CV_DbgAssert( _step >= minstep );`
`513`	`512`
`514`	`513`	`if (_step % esz1 != 0)`
`515`	`514`	`{`
`516`	`515`	`CV_Error(Error::BadStep, "Step must be a multiple of esz1");`
`517`	`516`	`}`
`518`	`517`
`519`		`- flags \|= _step == minstep ? CONTINUOUS_FLAG : 0;`
	`518`	`+ if (_step == minstep \|\| rows == 1)`
	`519`	`+ flags \|= CONTINUOUS_FLAG;`
`520`	`520`	`}`
`521`	`521`	`step[0] = _step;`
`522`	`522`	`step[1] = esz;`
`@@ -541,15 +541,15 @@ Mat::Mat(Size _sz, int _type, void* _data, size_t _step)`
`541`	`541`	`}`
`542`	`542`	`else`
`543`	`543`	`{`
`544`		`- if( rows == 1 ) _step = minstep;`
`545`	`544`	`CV_DbgAssert( _step >= minstep );`
`546`	`545`
`547`	`546`	`if (_step % esz1 != 0)`
`548`	`547`	`{`
`549`	`548`	`CV_Error(Error::BadStep, "Step must be a multiple of esz1");`
`550`	`549`	`}`
`551`	`550`
`552`		`- flags \|= _step == minstep ? CONTINUOUS_FLAG : 0;`
	`551`	`+ if (_step == minstep \|\| rows == 1)`
	`552`	`+ flags \|= CONTINUOUS_FLAG;`
`553`	`553`	`}`
`554`	`554`	`step[0] = _step;`
`555`	`555`	`step[1] = esz;`