diff --git a/src/bufr_util.c b/src/bufr_util.c
index d22b809f4..21842a3fe 100644
--- a/src/bufr_util.c
+++ b/src/bufr_util.c
@@ -590,7 +590,7 @@ static int count_bufr_messages(grib_context* c, FILE* f, int* n, int strict_mode
             err = GRIB_INTERNAL_ERROR;
         }
     }
-
+    (void)done;
     rewind(f);
     if (err == GRIB_END_OF_FILE)
         err = GRIB_SUCCESS;
diff --git a/src/grib_accessor_class_data_g1second_order_row_by_row_packing.c b/src/grib_accessor_class_data_g1second_order_row_by_row_packing.c
index ffabc88b1..c6c76fc5a 100644
--- a/src/grib_accessor_class_data_g1second_order_row_by_row_packing.c
+++ b/src/grib_accessor_class_data_g1second_order_row_by_row_packing.c
@@ -249,7 +249,7 @@ static int value_count(grib_accessor* a, long* count)
         long *bitmap, *pbitmap;
         size_t numberOfPoints = 0;
 
-        if (plSize) {
+        if (plSize && pl) {
             for (i = 0; i < numberOfRows; i++)
                 numberOfPoints += pl[i];
             grib_context_free(c, pl);
@@ -342,7 +342,7 @@ static int unpack_double(grib_accessor* a, double* values, size_t* len)
         long *bitmap, *pbitmap;
         size_t numberOfPoints = Ni * Nj;
 
-        if (plSize) {
+        if (plSize && pl) {
             numberOfPoints = 0;
             for (i = 0; i < numberOfRows; i++)
                 numberOfPoints += pl[i];
@@ -350,7 +350,7 @@ static int unpack_double(grib_accessor* a, double* values, size_t* len)
         bitmap  = (long*)grib_context_malloc_clear(a->context, sizeof(long) * numberOfPoints);
         pbitmap = bitmap;
         grib_get_long_array(gh, self->bitmap, bitmap, &numberOfPoints);
-        if (plSize) {
+        if (plSize && pl) {
             for (i = 0; i < numberOfRows; i++) {
                 for (j = 0; j < pl[i]; j++) {
                     numbersPerRow[i] += *(bitmap++);
@@ -369,7 +369,7 @@ static int unpack_double(grib_accessor* a, double* values, size_t* len)
         grib_context_free(a->context, pbitmap);
     }
     else {
-        if (plSize) {
+        if (plSize && pl) {
             for (i = 0; i < numberOfRows; i++)
                 numbersPerRow[i] = pl[i];
         }
diff --git a/src/grib_accessor_class_gen.c b/src/grib_accessor_class_gen.c
index e6d51763a..797cf5145 100644
--- a/src/grib_accessor_class_gen.c
+++ b/src/grib_accessor_class_gen.c
@@ -593,8 +593,9 @@ static int is_missing(grib_accessor* a)
     if (a->flags & GRIB_ACCESSOR_FLAG_TRANSIENT) {
         if (a->vvalue == NULL) {
             grib_context_log(a->context, GRIB_LOG_ERROR, "%s internal error (flags=0x%X)", a->name, a->flags);
+            Assert(!"grib_accessor_class_gen::is_missing(): a->vvalue == NULL");
+            return 0;
         }
-        Assert(a->vvalue != NULL);
         return a->vvalue->missing;
     }
     Assert(a->length >= 0);
diff --git a/src/grib_accessor_class_md5.c b/src/grib_accessor_class_md5.c
index 6c646b563..bb6603820 100644
--- a/src/grib_accessor_class_md5.c
+++ b/src/grib_accessor_class_md5.c
@@ -146,7 +146,7 @@ static void init(grib_accessor* a, const long len, grib_arguments* arg)
 
     self->offset    = grib_arguments_get_name(grib_handle_of_accessor(a), arg, n++);
     self->length    = grib_arguments_get_expression(grib_handle_of_accessor(a), arg, n++);
-    self->blacklist = 0;
+    self->blacklist = NULL;
     while ((b = (char*)grib_arguments_get_name(grib_handle_of_accessor(a), arg, n++)) != NULL) {
         if (!self->blacklist) {
             self->blacklist        = (grib_string_list*)grib_context_malloc_clear(context, sizeof(grib_string_list));
@@ -154,9 +154,12 @@ static void init(grib_accessor* a, const long len, grib_arguments* arg)
             current                = self->blacklist;
         }
         else {
-            current->next        = (grib_string_list*)grib_context_malloc_clear(context, sizeof(grib_string_list));
-            current->next->value = grib_context_strdup(context, b);
-            current              = current->next;
+            Assert(current);
+            if (current) {
+                current->next        = (grib_string_list*)grib_context_malloc_clear(context, sizeof(grib_string_list));
+                current->next->value = grib_context_strdup(context, b);
+                current              = current->next;
+            }
         }
     }
     a->length = 0;
diff --git a/src/grib_expression.c b/src/grib_expression.c
index 60580d942..b2fd9fdab 100644
--- a/src/grib_expression.c
+++ b/src/grib_expression.c
@@ -67,7 +67,7 @@ const char* grib_expression_get_name(grib_expression* g)
             return c->get_name(g);
         c = c->super ? *(c->super) : NULL;
     }
-    printf("No expression_get_name() in %s\n", g->cclass->name);
+    if (g->cclass) printf("No expression_get_name() in %s\n", g->cclass->name);
     Assert(1 == 0);
     return 0;
 }
diff --git a/src/grib_ieeefloat.c b/src/grib_ieeefloat.c
index c27aa4830..5e8851895 100644
--- a/src/grib_ieeefloat.c
+++ b/src/grib_ieeefloat.c
@@ -130,7 +130,7 @@ unsigned long grib_ieee_to_long(double x)
     unsigned long s    = 0;
     unsigned long mmax = 0xffffff;
     unsigned long mmin = 0x800000;
-    unsigned long m    = mmax;
+    unsigned long m    = 0;
     unsigned long e    = 0;
     double rmmax       = mmax + 0.5;
 
diff --git a/tools/grib_to_netcdf.c b/tools/grib_to_netcdf.c
index 67e8de3e4..379fc24f1 100644
--- a/tools/grib_to_netcdf.c
+++ b/tools/grib_to_netcdf.c
@@ -2549,13 +2549,14 @@ static void scale_bitmap(double* vals, long n, void* data, dataset_t* subset)
     int i          = 0;
     nc_type nctype = subset->att.nctype;
 
-    /*
-     if(!subset->bitmap)
-     {
-      grib_context_log(ctx,GRIB_LOG_DEBUG,"No scale of bitmap required");
-      return;
-     }
-     */
+    /* if(!subset->bitmap) {
+        grib_context_log(ctx,GRIB_LOG_DEBUG,"No scale of bitmap required");
+        return;
+     } */
+    if (n > 0 && !vals) {
+        Assert(!"scale_bitmap: n > 0 but vals == NULL");
+        return;
+    }
 
     switch (nctype) {
         case NC_BYTE: {