DXF: INSERT missed when it is the last entity and DXF_MERGE_BLOCK_GEOMETRIES is false

[Alan Thomas]

The attached DXF file has only one entity, an INSERT. Importantly, the block being inserted contains more than one geometry. When opened with --config DXF_MERGE_BLOCK_GEOMETRIES FALSE, the file appears empty:

$ ogrinfo -sql "SELECT * FROM Entities" -geom=summary --config DXF_MERGE_BLOCK_GEOMETRIES FALSE insert-only.dxf
DXF ASCII and binary is not supported yet.Warning 4: Failed to open insert-only.dxf, No error.
Had to open data source read-only.
INFO: Open of `insert-only.dxf'
      using driver `DXF' successful.

Layer name: Entities
Geometry: Unknown (any)
Feature Count: 0
Layer SRS WKT:
(unknown)
Geometry Column = _ogr_geometry_
Layer: String (0.0)
SubClasses: String (0.0)
ExtendedEntity: String (0.0)
Linetype: String (0.0)
EntityHandle: String (0.0)
Text: String (0.0)

(by the way, what is with the bogus "ASCII and binary" warning at the top of the output?)

See attached patch for a potential fix to allow this file to be imported correctly.

[Alan Thomas]

Patch

[Even Rouault]

In 39837:

CAD: do not emit warning on .dxf files (if registered before the DXF driver) (refs #7006)

[Even Rouault]

In 39839:

DXF: fix reading files where INSERT is the last entity and DXF_MERGE_BLOCK_GEOMETRIES is false (patch by atlight, test by myself, fixes #7006)

[Even Rouault]

In 39840:

DXF: fix reading files where INSERT is the last entity and DXF_MERGE_BLOCK_GEOMETRIES is false (patch by atlight, test by myself, fixes #7006)