fixed pgr_pointsAsPolygon breaking when comparing strings in WHERE clause

[iboates]

Fixes #1192 .

Changes proposed in this pull request:

• Replace single quotes in the query passed to pgr_pointsAsPolygon() with escaped quotes, stopping a failure if a string comparison is specified in its WHERE clause in the subsequent call to pgr_alphaShape()

@pgRouting/admins

[iboates]

You can use this query to test with & without this update.

Before, it should throw a syntax error from pgr_alphaShape. After, it should execute as normal.

CREATE TABLE public.alphashape_fix_points (
    id bigint,
    text_col text,
    the_geom public.geometry(Point,3003)
);

INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (314, 'bar', '0101000020BB0B000021D0019EC1DC34417032CFFC89E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (102, 'foo', '0101000020BB0B0000BC9FD33AB2DC34418E9F3117A0E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (154, 'foo', '0101000020BB0B000095F46493E8DC3441C12686009EE55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (155, 'foo', '0101000020BB0B00001323185411DD34416C91D66695E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (156, 'foo', '0101000020BB0B0000C6003C87D0DC3441AF61D39E90E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (157, 'foo', '0101000020BB0B00008A7AD07FFADC3441301C9D128BE55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (161, 'foo', '0101000020BB0B00000E23A4F1E0DC34416B866E7FA2E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (190, 'bar', '0101000020BB0B0000C90607B0DBDC3441B94BD31B97E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (191, 'bar', '0101000020BB0B0000F438DD6204DD3441D064C81E91E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (237, 'bar', '0101000020BB0B0000734B2DA702DD34416F1074FD8FE55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (251, 'bar', '0101000020BB0B0000B77FE51FF4DC34415AC8EBFE83E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (276, 'bar', '0101000020BB0B0000AE212EF2EBDC344101CE9DA2A0E55241');
INSERT INTO public.alphashape_fix_points (id, text_col, the_geom) VALUES (285, 'bar', '0101000020BB0B00003E7ECA0CCCDC34414BF56E23A1E55241');

SELECT
    pgr_pointsAsPolygon(
        'SELECT
            id::INT4,
            ST_X(the_geom)::float AS x,
            ST_Y(the_geom)::float AS y
        FROM
            work.cur_net_vertices_pgr
        WHERE
            text_col =  ''foo'';'
);

[cvvergara]

Hello @iboates
I really don't understand the error being fixed, but I trust you :)

There is a typo on a test file (I really dont know how it came to pgRouting
https://github.com/pgRouting/pgrouting/blob/master/pgtap/common/hasnt_v2_signatures.sql#L33
Can you change from this:

SELECT hasnt_function('pgr_tsp',ARRAY['(double precision[]', 'integer', 'integer']);

to this

SELECT hasnt_function('pgr_tsp',ARRAY['double precision[]', 'integer', 'integer']);

in your PR, so that tests pass and then I am able to merge please

FYI,
This function will be deprecated on v3.0.0
because of #1188

I would really appreciate if you try the new function on some real data
https://docs.pgrouting.org/dev/en/pgr_alphaShape.html

[iboates]

@cvvergara Is there still a separate function for pgr_alphaShape and pgr_pointsFromPolygon? All I see is a single function for pgr_alphaShape here: https://github.com/pgRouting/pgrouting/blob/develop/sql/alpha_shape/alphaShape.sql

[cvvergara]

@iboates
we are only keeping one function
when those functions were introduced:
pgr_pointsAsPolygons calls the pgr_alphaShape that does the calculation, like the backend, but with the name pgr_pointsAsPolygons it could easily call ST_ConcaveHull which gives a polygon as result or ST_ConvexHull which also give a polygon as result.

_pgr_alphaShape (its the backend & does the calculation) & pgr_alphaShape(pre calculates the delauny triangles and calls the backend function) <--- so things look like this now (on v3.0.0 for sep)

[iboates]

@cvvergara I tested on the 3.0.0 development docker image and it is no longer an issue. The fact that the geometry is passed directly and not via a SQL string means that there is no problem with characters becoming unescaped.

[iboates]

@cvvergara Tests now pass