Throw on invalid characters when decoding geohash

References #4406

git-svn-id: http://svn.osgeo.org/postgis/branches/2.5@17528 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/NEWS b/NEWS
index 181ece7c245155f09ca0349eb9f6abce1b80b338..5e9bcd2c8a92677fad0567365a1f39cc9bd8533e 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,7 @@ PostGIS 2.5.3
   - #4380, Simple TIN support to allow viz in QGIS (Paul Ramsey)
   - #4388, AddRasterConstraints: Ignore NULLs when generating constraints (Raúl Marín)
   - #4327, Avoid pfree'ing the result of getenv (Raúl Marín)
+  - #4406, Throw on invalid characters when decoding geohash (Raúl Marín)
 
 
 PostGIS 2.5.2

diff --git a/liblwgeom/cunit/cu_algorithm.c b/liblwgeom/cunit/cu_algorithm.c
index 988533f77327dd7082b284329e0bed7e6a7092c3..9be12e87316574adb925267b11c3c4c3235558eb 100644 (file)
--- a/liblwgeom/cunit/cu_algorithm.c
+++ b/liblwgeom/cunit/cu_algorithm.c
@@ -1038,6 +1038,23 @@ static void test_lwgeom_remove_repeated_points(void)
        lwfree(ewkt);
 }
 
+static void
+test_geohash_bbox(void)
+{
+       double lat[2], lon[2];
+
+       /* SELECT ST_GeoHash(ST_SetSRID(ST_MakePoint(-126,48),4326)) */
+       decode_geohash_bbox("c0w3hf1s70w3hf1s70w3", lat, lon, 100);
+       CU_ASSERT_DOUBLE_EQUAL(lat[0], 48, 1e-11);
+       CU_ASSERT_DOUBLE_EQUAL(lat[1], 48, 1e-11);
+       CU_ASSERT_DOUBLE_EQUAL(lon[0], -126, 1e-11);
+       CU_ASSERT_DOUBLE_EQUAL(lon[1], -126, 1e-11);
+
+       cu_error_msg_reset();
+       decode_geohash_bbox("@@@@@@", lat, lon, 100);
+       ASSERT_STRING_EQUAL(cu_error_msg, "decode_geohash_bbox: Invalid character '@'");
+}
+
 static void test_lwgeom_simplify(void)
 {
        LWGEOM *l;
@@ -1503,6 +1520,7 @@ void algorithms_suite_setup(void)
        PG_ADD_TEST(suite,test_geohash_precision);
        PG_ADD_TEST(suite,test_geohash);
        PG_ADD_TEST(suite,test_geohash_point_as_int);
+       PG_ADD_TEST(suite, test_geohash_bbox);
        PG_ADD_TEST(suite,test_isclosed);
        PG_ADD_TEST(suite,test_lwgeom_simplify);
        PG_ADD_TEST(suite,test_lw_arc_center);

diff --git a/liblwgeom/lwalgorithm.c b/liblwgeom/lwalgorithm.c
index 172014418e36b536082fa93381204f5eabeb83ff..f81f492762bcd705eb577b7a70f4d472cff9383b 100644 (file)
--- a/liblwgeom/lwalgorithm.c
+++ b/liblwgeom/lwalgorithm.c
@@ -709,6 +709,7 @@ unsigned int geohash_point_as_int(POINT2D *pt)
 ** set in them will be the southwest and northeast coordinates of the bounding
 ** box accordingly. A precision less than 0 indicates that the entire length
 ** of the GeoHash should be used.
+** It will call `lwerror` if an invalid character is found
 */
 void decode_geohash_bbox(char *geohash, double *lat, double *lon, int precision)
 {
@@ -731,6 +732,13 @@ void decode_geohash_bbox(char *geohash, double *lat, double *lon, int precision)
        for (i = 0; i < precision; i++)
        {
                c = tolower(geohash[i]);
+               /* Valid characters are all digits and letters except a, i, l and o */
+               if (!(((c >= '0') && (c <= '9')) ||
+                     ((c >= 'b') && (c <= 'z') && (c != 'i') && (c != 'l') && (c != 'o'))))
+               {
+                       lwerror("%s: Invalid character '%c'", __func__, geohash[i]);
+                       return;
+               }
                cd = strchr(base32, c) - base32;
 
                for (j = 0; j < 5; j++)