[postgis-tickets] [PostGIS] #4451: gserialized_max_header_size is too big

[PostGIS]

#4451: gserialized_max_header_size is too big
------------------------+---------------------------
 Reporter:  Algunenano  |      Owner:  Algunenano
     Type:  defect      |     Status:  assigned
 Priority:  medium      |  Milestone:  PostGIS 3.0.0
Component:  postgis     |    Version:  trunk
 Keywords:              |
------------------------+---------------------------
 The max header size is being calculated as:
 {{{
 return sizeof(GSERIALIZED) + 8 * sizeof(float) + sizeof(int);
 }}}

 But sizeof(GSERIALIZED) takes into account `data[1]`, which AFAIK we
 shouldn't include as it's added after.

 A small test case:
 {{{
 #include <stdio.h>
 #include <stdint.h>

 typedef struct
 {
     uint32_t size; /* For PgSQL use only, use VAR* macros to manipulate.
 */
     uint8_t srid[3]; /* 24 bits of SRID */
     uint8_t gflags; /* HasZ, HasM, HasBBox, IsGeodetic */
     uint8_t data[1]; /* See gserialized.txt */
 } GSERIALIZED;

 int main()
 {
         printf("Size: %d\n", sizeof(GSERIALIZED));
         printf("Data: %u\n", (intptr_t)&((GSERIALIZED *)NULL)->data);
 }
 }}}

 {{{
 $ ./a.out
 Size: 12
 Data: 8
 }}}

 sizeof(GSERIALIZED) returns 12 bytes, when what we want is 8.

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/4451>
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