Do not free the PROJ4 pointers at levels > 1. (#8390)

Whith nested calls, as for example pscoast -E, if projections are done with PROJ4 we need those pointers alive when plotting the grid lines that happens only at the end.

src/gmt_init.c

@@ -16479,21 +16479,26 @@ struct GMT_CTRL * gmt_begin_module (struct GMTAPI_CTRL *API, const char *lib_nam
 /*! . */
 void gmt_end_module (struct GMT_CTRL *GMT, struct GMT_CTRL *Ccopy) {
  unsigned int i, V_level = GMT->current.setting.verbose; /* Keep copy of currently selected level */
+ unsigned int func_level_bak = GMT->hidden.func_level;
  bool pass_changes_back;
  struct GMT_DEFAULTS saved_settings;
  double spacing[2];
+ OGRCoordinateTransformationH hCT_fwd_bak;
+ OGRCoordinateTransformationH hCT_inv_bak;
 
  GMT->parent->use_gridline_registration = false; /* Reset API default setting on grid registration */
  GMT->parent->use_gridline_registration_warn = false; /* Reset API default setting on grid registration warning */
 
  gmt_M_memcpy (spacing, GMT->current.plot.gridline_spacing, 2U, double); /* Remember these so they can survive the end of the module */
 
  /* If that's the case, clean up any GDAL CT object */
- if (GMT->current.gdal_read_in.hCT_fwd)
- OCTDestroyCoordinateTransformation(GMT->current.gdal_read_in.hCT_fwd);
- if (GMT->current.gdal_read_in.hCT_inv)
- OCTDestroyCoordinateTransformation(GMT->current.gdal_read_in.hCT_inv);
- GMT->current.gdal_read_in.hCT_fwd = GMT->current.gdal_read_in.hCT_inv = NULL;
+ if (GMT->hidden.func_level == GMT_TOP_MODULE) { /* Don't free these on nested calls because they may still be needed. */
+ if (GMT->current.gdal_read_in.hCT_fwd)
+ OCTDestroyCoordinateTransformation(GMT->current.gdal_read_in.hCT_fwd);
+ if (GMT->current.gdal_read_in.hCT_inv)
+ OCTDestroyCoordinateTransformation(GMT->current.gdal_read_in.hCT_inv);
+ GMT->current.gdal_read_in.hCT_fwd = GMT->current.gdal_read_in.hCT_inv = NULL;
+ }
 
  if (GMT->hidden.func_level == GMT_TOP_MODULE && GMT->current.ps.oneliner && GMT->current.ps.active) {
  char *setting = getenv ("GMT_END_SHOW");
@@ -16673,7 +16678,19 @@ void gmt_end_module (struct GMT_CTRL *GMT, struct GMT_CTRL *Ccopy) {
  GMT->current.setting.io_lonlat_toggle[GMT_IN] = GMT->current.setting.io_lonlat_toggle[GMT_OUT] = false;
 
  /* Reset these GDAL in/out stuff */
+ /* So, here the story for the need of the following. pscoast when used with DCW and a PROJ4 string call psxy
+ to do the line plot bau still needs to give hand to pscoast again to plot eventual grid lines. Se we can't
+ destroy the proj functions until the func_level == 1
+ */
+ if (func_level_bak > GMT_TOP_MODULE) {
+ hCT_fwd_bak = GMT->current.gdal_read_in.hCT_fwd;
+ hCT_inv_bak = GMT->current.gdal_read_in.hCT_inv;
+ }
  gmt_M_memset (&GMT->current.gdal_read_in, 1, struct GMT_GDALREAD_IN_CTRL);
+ if (func_level_bak > GMT_TOP_MODULE && hCT_fwd_bak) {
+ GMT->current.gdal_read_in.hCT_fwd = hCT_fwd_bak;
+ GMT->current.gdal_read_in.hCT_inv = hCT_inv_bak;
+ }
  gmt_M_memset (&GMT->current.gdal_read_out, 1, struct GMT_GDALREAD_OUT_CTRL);
  gmt_M_memset (&GMT->current.gdal_write, 1, struct GMT_GDALWRITE_CTRL);
 
@@ -18512,6 +18529,8 @@ int gmt_parse_common_options (struct GMT_CTRL *GMT, char *list, char option, cha
  if (GMT->current.proj.projection_GMT != GMT_LINEAR)
  GMT->current.proj.proj4_is_cart[1] = true;
  }
+ if (GMT->current.gdal_read_in.hCT_fwd) OCTDestroyCoordinateTransformation(GMT->current.gdal_read_in.hCT_fwd);
+ if (GMT->current.gdal_read_in.hCT_inv) OCTDestroyCoordinateTransformation(GMT->current.gdal_read_in.hCT_inv);
  GMT->current.gdal_read_in.hCT_fwd = gmt_OGRCoordinateTransformation (GMT, source, dest);
  GMT->current.gdal_read_in.hCT_inv = gmt_OGRCoordinateTransformation (GMT, dest, source);
  GMT->current.proj.projection = GMT_PROJ4_PROJS; /* This now make it use the proj4 lib */