A problem with corrupted files about matio HOT 7 OPEN

diff --git a/src/mat.c b/src/mat.c
index 9c48578..20370db 100644
--- a/src/mat.c
+++ b/src/mat.c
@@ -506,6 +506,7 @@ Mat_Open(const char *matname, int mode)
     mat->version = 0;
     mat->byteswap = 0;
     mat->num_datasets = 0;
+    mat->struct_vars_limit = 0;
 #if defined(MAT73) && MAT73
     mat->refs_id = -1;
 #endif
@@ -2967,3 +2968,17 @@ Mat_VarWriteAppend(mat_t *mat, matvar_t *matvar, enum matio_compression compress
 
     return err;
 }
+
+/** @brief Limit max number of variables to allocate memory for
+ *
+ * This sets a limit on maximum number of variables which may be allocated for a struct.
+ * max number of variables is number of struct members * number of elements per member.
+ * By default there is not limit.
+ * @ingroup MAT
+ * @param mat MAT file
+ * @param limit max number of variables in the struct
+ */
+void Mat_VarSetSrtuctVarsLimit(mat_t *mat, size_t limit)
+{
+    mat->struct_vars_limit = limit;
+}
diff --git a/src/mat5.c b/src/mat5.c
index eb4b384..258b0d7 100644
--- a/src/mat5.c
+++ b/src/mat5.c
@@ -1468,6 +1468,10 @@ ReadNextStructField(mat_t *mat, matvar_t *matvar)
         if ( !matvar->nbytes )
             return bytesread;
 
+        if (mat->struct_vars_limit && nelems_x_nfields > mat->struct_vars_limit) {
+            Mat_Critical("Struct vars limit exceeded. Allocation failed");
+            return bytesread;
+        }
         matvar->data = calloc(nelems_x_nfields, matvar->data_size);
         if ( NULL == matvar->data ) {
             Mat_Critical("Couldn't allocate memory for the data");
@@ -1739,6 +1743,10 @@ ReadNextStructField(mat_t *mat, matvar_t *matvar)
         if ( !matvar->nbytes )
             return bytesread;
 
+        if (mat->struct_vars_limit && nelems_x_nfields > mat->struct_vars_limit) {
+            Mat_Critical("Struct vars limit exceeded. Allocation failed");
+            return bytesread;
+        }
         matvar->data = calloc(nelems_x_nfields, matvar->data_size);
         if ( NULL == matvar->data ) {
             Mat_Critical("Couldn't allocate memory for the data");
diff --git a/src/matio.h b/src/matio.h
index 8a4caeb..78e7168 100644
--- a/src/matio.h
+++ b/src/matio.h
@@ -347,6 +347,7 @@ EXTERN int Mat_VarWriteAppend(mat_t *mat, matvar_t *matvar, enum matio_compressi
 EXTERN int Mat_VarWriteInfo(mat_t *mat, matvar_t *matvar);
 EXTERN int Mat_VarWriteData(mat_t *mat, matvar_t *matvar, void *data, int *start, int *stride,
                             int *edge);
+EXTERN void Mat_VarSetSrtuctVarsLimit(mat_t *mat, size_t limit);
 
 /* Other functions */
 EXTERN int Mat_CalcSingleSubscript(int rank, int *dims, int *subs);
diff --git a/src/matio_private.h b/src/matio_private.h
index d6d22b6..51f9594 100644
--- a/src/matio_private.h
+++ b/src/matio_private.h
@@ -113,6 +113,7 @@ struct _mat_t
     mat_off_t bof;       /**< Beginning of file not including any header */
     size_t next_index;   /**< Index/File position of next variable to read */
     size_t num_datasets; /**< Number of datasets in the file */
+    size_t struct_vars_limit; /**< A limit to max number of variable in a struct. n_members * n_elems_per_member */
 #if defined(MAT73) && MAT73
     hid_t refs_id; /**< Id of the /#refs# group in HDF5 */
 #endif