Don't let lwgeom_add_bbox syntetize a fake box for empty geometries

Empty geometries have no box. Period.
Update GML extent output for empty geometries to handle the special
case by using empty tags. Regress test it.

git-svn-id: http://svn.osgeo.org/postgis/trunk@8334 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/liblwgeom/cunit/cu_out_gml.c b/liblwgeom/cunit/cu_out_gml.c
index 3bb47725acd6996b34a5557993a53ae256993827..f0a5f45eba446495c6e2d97c4f12de729b4c7d4c 100644 (file)
--- a/liblwgeom/cunit/cu_out_gml.c
+++ b/liblwgeom/cunit/cu_out_gml.c
@@ -176,7 +176,7 @@ static void do_gml2_extent_test(char * in, char * out, char * srs,
 
        g = lwgeom_from_wkt(in, LW_PARSER_CHECK_NONE);
        h = lwgeom_extent_to_gml2(g, srs, precision, prefix);
-       if ( ! h ) h = cu_error_msg;
+       if ( ! h ) h = strdup(cu_error_msg);
 
        if (strcmp(h, out))
                fprintf(stderr, "\nEXT GML 2 - In:   %s\nObt: %s\nExp: %s\n",
@@ -196,7 +196,7 @@ static void do_gml3_extent_test(char * in, char * out, char * srs,
 
        g = lwgeom_from_wkt(in, LW_PARSER_CHECK_NONE);
        h = lwgeom_extent_to_gml3(g, srs, precision, opts, prefix);
-       if ( ! h ) h = cu_error_msg;
+       if ( ! h ) h = strdup(cu_error_msg);
 
        if (strcmp(h, out))
                fprintf(stderr, "\nEXT GML 3 - In:   %s\nObt: %s\nExp: %s\n",
@@ -1037,12 +1037,18 @@ static void out_gml2_extent(void)
            "<Box><coordinates>-2,-1 10,14</coordinates></Box>",
            NULL, 15, "");
 
-       /* GML2: empty (FIXME) */
+       /* GML2: empty */
        do_gml2_extent_test(
            "GEOMETRYCOLLECTION EMPTY",
-           "<Box><coordinates>0,0 0,0</coordinates></Box>",
+           "<Box/>",
            NULL, 15, "");
 
+       /* GML2: empty with srsName */
+       do_gml2_extent_test(
+           "GEOMETRYCOLLECTION EMPTY",
+           "<Box srsName=\"urn:ogc:def:crs:EPSG::4326\"/>",
+           "urn:ogc:def:crs:EPSG::4326", 15, "");
+
 }
 
 static void out_gml3_extent(void)
@@ -1109,12 +1115,18 @@ static void out_gml3_extent(void)
            "<Envelope><lowerCorner>-2 -1</lowerCorner><upperCorner>10 14</upperCorner></Envelope>",
            NULL, 15, 0, "");
 
-       /* GML3: empty (FIXME) */
+       /* GML3: empty */
        do_gml3_extent_test(
            "GEOMETRYCOLLECTION EMPTY",
-           "<Envelope><lowerCorner>0 0</lowerCorner><upperCorner>0 0</upperCorner></Envelope>",
+           "<Envelope/>",
            NULL, 15, 0, "");
 
+       /* GML3: empty with srsName */
+       do_gml3_extent_test(
+           "GEOMETRYCOLLECTION EMPTY",
+           "<Envelope srsName=\"urn:ogc:def:crs:EPSG::4326\"/>",
+           "urn:ogc:def:crs:EPSG::4326", 15, 0, "");
+
 }
 
 

diff --git a/liblwgeom/lwgeom.c b/liblwgeom/lwgeom.c
index ae1dc47a3df026c40f67fb70aad1801ab294078f..20bab78f299933600396260b51be92acbdc508b6 100644 (file)
--- a/liblwgeom/lwgeom.c
+++ b/liblwgeom/lwgeom.c
@@ -542,6 +542,9 @@ lwgeom_drop_bbox(LWGEOM *lwgeom)
 void
 lwgeom_add_bbox(LWGEOM *lwgeom)
 {
+       /* an empty LWGEOM has no bbox */
+       if( lwgeom_is_empty(lwgeom) ) return;
+
        if ( lwgeom->bbox ) return;
        FLAGS_SET_BBOX(lwgeom->flags, 1);
        lwgeom->bbox = gbox_new(lwgeom->flags);

diff --git a/liblwgeom/lwout_gml.c b/liblwgeom/lwout_gml.c
index 2b2c151997fbb7dcea6381c6ed368ce25454bb05..df7b83f42733a5b5798aad86446a74d0f1f89ebe 100644 (file)
--- a/liblwgeom/lwout_gml.c
+++ b/liblwgeom/lwout_gml.c
@@ -70,6 +70,21 @@ gbox_to_gml2(const GBOX *bbox, const char *srs, int precision, const char *prefi
        char *ptr, *output;
        size_t prefixlen = strlen(prefix);
 
+       if ( ! bbox ) {
+               size = ( sizeof("<Box>/") + (prefixlen*2) ) * 2;
+               if ( srs ) size += strlen(srs) + sizeof(" srsName=..");
+
+               ptr = output = lwalloc(size);
+
+               ptr += sprintf(ptr, "<%sBox", prefix);
+
+               if ( srs ) ptr += sprintf(ptr, " srsName=\"%s\"", srs);
+
+               ptr += sprintf(ptr, "/>");
+
+               return output;
+       }
+
         pa = ptarray_construct_empty(FLAGS_GET_Z(bbox->flags), 0, 2);
 
         pt.x = bbox->xmin; 
@@ -110,6 +125,20 @@ gbox_to_gml3(const GBOX *bbox, const char *srs, int precision, int opts, const c
        size_t prefixlen = strlen(prefix);
        int dimension = 2;
 
+       if ( ! bbox ) {
+               size = ( sizeof("<Envelope>/") + (prefixlen*2) ) * 2;
+               if ( srs ) size += strlen(srs) + sizeof(" srsName=..");
+
+               ptr = output = lwalloc(size);
+
+               ptr += sprintf(ptr, "<%sEnvelope", prefix);
+               if ( srs ) ptr += sprintf(ptr, " srsName=\"%s\"", srs);
+
+               ptr += sprintf(ptr, "/>");
+
+               return output;
+       }
+
         if (FLAGS_GET_Z(bbox->flags)) dimension = 3;
 
         pa = ptarray_construct_empty(FLAGS_GET_Z(bbox->flags), 0, 1);
@@ -157,10 +186,12 @@ extern char *
 lwgeom_extent_to_gml2(const LWGEOM *geom, const char *srs, int precision, const char *prefix)
 {
        const GBOX* bbox = lwgeom_get_bbox(geom);
+/*
        if ( ! bbox ) {
                lwerror("lwgeom_extent_to_gml2: empty geometry doesn't have a bounding box");
                return NULL;
        }
+*/
        char *ret = gbox_to_gml2(bbox, srs, precision, prefix);
        return ret;
 }
@@ -170,10 +201,12 @@ extern char *
 lwgeom_extent_to_gml3(const LWGEOM *geom, const char *srs, int precision, int opts, const char *prefix)
 {
        const GBOX* bbox = lwgeom_get_bbox(geom);
+/*
        if ( ! bbox ) {
                lwerror("lwgeom_extent_to_gml3: empty geometry doesn't have a bounding box");
                return NULL;
        }
+*/
        return gbox_to_gml3(bbox, srs, precision, opts, prefix);
 }