Don't read trailing datatype layout bytes when first_ptr==-1.

Author: maleadt

src/dump.c

@@ -403,7 +403,10 @@ static void jl_serialize_datatype(jl_serializer_state *s, jl_datatype_t *dt) JL_
             uint32_t np = dt->layout->npointers;
             size_t fieldsize = jl_fielddesc_size(dt->layout->fielddesc_type);
             ios_write(s->s, (const char*)dt->layout, sizeof(*dt->layout));
-            ios_write(s->s, (const char*)(dt->layout + 1), nf * fieldsize + (np << dt->layout->fielddesc_type));
+            size_t fldsize = nf * fieldsize;
+            if (dt->layout->first_ptr != -1)
+                fldsize += np << dt->layout->fielddesc_type;
+            ios_write(s->s, (const char*)(dt->layout + 1), fldsize);
         }
     }
 
@@ -1484,11 +1487,14 @@ static jl_value_t *jl_deserialize_datatype(jl_serializer_state *s, int pos, jl_v
             uint32_t np = buffer.npointers;
             uint8_t fielddesc_type = buffer.fielddesc_type;
             size_t fielddesc_size = nf > 0 ? jl_fielddesc_size(fielddesc_type) : 0;
+            size_t fldsize = nf * fielddesc_size;
+            if (buffer.first_ptr != -1)
+                fldsize += np << fielddesc_type;
             jl_datatype_layout_t *layout = (jl_datatype_layout_t*)jl_gc_perm_alloc(
-                    sizeof(jl_datatype_layout_t) + nf * fielddesc_size + (np << fielddesc_type),
+                    sizeof(jl_datatype_layout_t) + fldsize,
                     0, 4, 0);
             *layout = buffer;
-            ios_read(s->s, (char*)(layout + 1), nf * fielddesc_size + (np << fielddesc_type));
+            ios_read(s->s, (char*)(layout + 1), fldsize);
             dt->layout = layout;
         }
     }

src/staticdata.c

@@ -871,7 +871,9 @@ static void jl_write_values(jl_serializer_state *s)
                     size_t np = dt->layout->npointers;
                     size_t fieldsize = jl_fielddesc_size(dt->layout->fielddesc_type);
                     char *flddesc = (char*)dt->layout;
-                    size_t fldsize = sizeof(jl_datatype_layout_t) + nf * fieldsize + (np << dt->layout->fielddesc_type);
+                    size_t fldsize = sizeof(jl_datatype_layout_t) + nf * fieldsize;
+                    if (dt->layout->first_ptr != -1)
+                        fldsize += np << dt->layout->fielddesc_type;
                     uintptr_t layout = LLT_ALIGN(ios_pos(s->const_data), sizeof(void*));
                     write_padding(s->const_data, layout - ios_pos(s->const_data)); // realign stream
                     newdt->layout = NULL; // relocation offset