createOperations(): use more candidates when transforming between a geographic and vertical CRS

For example when transforming from NAD83+NAVD88 height to WGS84, there
is no transformation between NAVD88 height to WGS84. In that case,
use all potential transformations from NAVD88 height to another geographic CRS
for the vertical part.

1 files changed, 39 insertions, 30 deletions

diff --git a/src/iso19111/factory.cpp b/src/iso19111/factory.cpp
index 4bf5427d..3ed69ae9 100644
--- a/src/iso19111/factory.cpp
+++ b/src/iso19111/factory.cpp
@@ -3312,9 +3312,9 @@ AuthorityFactory::createFromCoordinateReferenceSystemCodes(
     bool discardSuperseded) const {
 
     auto cacheKey(d->authority());
-    cacheKey += sourceCRSAuthName;
+    cacheKey += sourceCRSAuthName.empty() ? "{empty}" : sourceCRSAuthName;
     cacheKey += sourceCRSCode;
-    cacheKey += targetCRSAuthName;
+    cacheKey += targetCRSAuthName.empty() ? "{empty}" : targetCRSAuthName;
     cacheKey += targetCRSCode;
     cacheKey += (usePROJAlternativeGridNames ? '1' : '0');
     cacheKey += (discardIfMissingGrid ? '1' : '0');
@@ -3326,27 +3326,30 @@ AuthorityFactory::createFromCoordinateReferenceSystemCodes(
         return list;
     }
 
-    // Look-up first for conversion which is the most precise.
-    std::string sql("SELECT conversion_auth_name, "
-                    "geodetic_crs_auth_name, geodetic_crs_code FROM "
-                    "projected_crs WHERE auth_name = ? AND code = ?");
-    auto params = ListOfParams{targetCRSAuthName, targetCRSCode};
-    auto res = d->run(sql, params);
-    if (!res.empty()) {
-        const auto &row = res.front();
-        bool ok = row[1] == sourceCRSAuthName && row[2] == sourceCRSCode;
-        if (ok && d->hasAuthorityRestriction()) {
-            ok = row[0] == d->authority();
-        }
-        if (ok) {
-            auto targetCRS = d->createFactory(targetCRSAuthName)
-                                 ->createProjectedCRS(targetCRSCode);
-            auto conv = targetCRS->derivingConversion();
-            list.emplace_back(conv);
-            d->context()->d->cache(cacheKey, list);
-            return list;
+    if (!targetCRSAuthName.empty()) {
+        // Look-up first for conversion which is the most precise.
+        std::string sql("SELECT conversion_auth_name, "
+                        "geodetic_crs_auth_name, geodetic_crs_code FROM "
+                        "projected_crs WHERE auth_name = ? AND code = ?");
+        auto params = ListOfParams{targetCRSAuthName, targetCRSCode};
+        auto res = d->run(sql, params);
+        if (!res.empty()) {
+            const auto &row = res.front();
+            bool ok = row[1] == sourceCRSAuthName && row[2] == sourceCRSCode;
+            if (ok && d->hasAuthorityRestriction()) {
+                ok = row[0] == d->authority();
+            }
+            if (ok) {
+                auto targetCRS = d->createFactory(targetCRSAuthName)
+                                     ->createProjectedCRS(targetCRSCode);
+                auto conv = targetCRS->derivingConversion();
+                list.emplace_back(conv);
+                d->context()->d->cache(cacheKey, list);
+                return list;
+            }
         }
     }
+    std::string sql;
     if (discardSuperseded) {
         sql = "SELECT cov.auth_name, cov.code, cov.table_name, "
               "ss.replacement_auth_name, ss.replacement_code FROM "
@@ -3358,20 +3361,26 @@ AuthorityFactory::createFromCoordinateReferenceSystemCodes(
               "ss.superseded_auth_name = cov.auth_name AND "
               "ss.superseded_code = cov.code AND "
               "ss.superseded_table_name = ss.replacement_table_name "
-              "WHERE source_crs_auth_name = ? AND source_crs_code = ? AND "
-              "target_crs_auth_name = ? AND target_crs_code = ? AND "
-              "cov.deprecated = 0";
+              "WHERE ";
     } else {
         sql = "SELECT cov.auth_name, cov.code, cov.table_name FROM "
               "coordinate_operation_view cov JOIN area "
               "ON cov.area_of_use_auth_name = area.auth_name AND "
               "cov.area_of_use_code = area.code "
-              "WHERE source_crs_auth_name = ? AND source_crs_code = ? AND "
-              "target_crs_auth_name = ? AND target_crs_code = ? AND "
-              "cov.deprecated = 0";
+              "WHERE ";
+    }
+    ListOfParams params;
+    if (!sourceCRSAuthName.empty()) {
+        sql += "source_crs_auth_name = ? AND source_crs_code = ? AND ";
+        params.emplace_back(sourceCRSAuthName);
+        params.emplace_back(sourceCRSCode);
+    }
+    if (!targetCRSAuthName.empty()) {
+        sql += "target_crs_auth_name = ? AND target_crs_code = ? AND ";
+        params.emplace_back(targetCRSAuthName);
+        params.emplace_back(targetCRSCode);
     }
-    params = {sourceCRSAuthName, sourceCRSCode, targetCRSAuthName,
-              targetCRSCode};
+    sql += "cov.deprecated = 0";
     if (d->hasAuthorityRestriction()) {
         sql += " AND cov.auth_name = ?";
         params.emplace_back(d->authority());
@@ -3379,7 +3388,7 @@ AuthorityFactory::createFromCoordinateReferenceSystemCodes(
     sql += " ORDER BY pseudo_area_from_swne(south_lat, west_lon, north_lat, "
            "east_lon) DESC, "
            "(CASE WHEN accuracy is NULL THEN 1 ELSE 0 END), accuracy";
-    res = d->run(sql, params);
+    auto res = d->run(sql, params);
     std::set<std::pair<std::string, std::string>> setTransf;
     if (discardSuperseded) {
         for (const auto &row : res) {