From ef0b0fe4d0ee708c490cf99bfcbd86e8cc009d2d Mon Sep 17 00:00:00 2001
From: Andreas Hocevar <andreas.hocevar@gmail.com>
Date: Thu, 2 Apr 2026 20:12:01 +0200
Subject: [PATCH] Broaden longc -> long0 assignment

---
 index.js           | 6 +++---
 test-fixtures.json | 6 ++++++
 util.js            | 4 ++--
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/index.js b/index.js
index 54b1ed7..29c5039 100644
--- a/index.js
+++ b/index.js
@@ -94,9 +94,9 @@ function setPropertiesFromWkt(wkt) {
     geogcs = wkt;
   }
   if (geogcs) {
-    //if(wkt.GEOGCS.PRIMEM&&wkt.GEOGCS.PRIMEM.convert){
-    //  wkt.from_greenwich=wkt.GEOGCS.PRIMEM.convert*D2R;
-    //}
+    if (geogcs.PRIMEM && geogcs.PRIMEM.convert) {
+      wkt.from_greenwich = d2r(geogcs.PRIMEM.convert);
+    }
     if (geogcs.DATUM) {
       wkt.datumCode = geogcs.DATUM.name.toLowerCase();
     } else {
diff --git a/test-fixtures.json b/test-fixtures.json
index dcf703b..68041d0 100644
--- a/test-fixtures.json
+++ b/test-fixtures.json
@@ -723,6 +723,7 @@
     "x0": 600000,
     "y0": 200000,
     "longc": 0.12984522414316144,
+    "long0": 0.12984522414316144,
     "lat0": 0.8194740686761227,
     "alpha": 1.570796326794897,
     "rectified_grid_angle": 1.570796326794897,
@@ -745,6 +746,7 @@
     "x0": 600000,
     "y0": 200000,
     "longc": 0.12984522414316635,
+    "long0": 0.12984522414316635,
     "lat0": 0.8194740686761263,
     "alpha": 1.570796326794897,
     "rectified_grid_angle": 1.570796326794897,
@@ -767,6 +769,7 @@
     "x0": 600000,
     "y0": 200000,
     "longc": 0.1298452241431614,
+    "long0": 0.1298452241431614,
     "lat0": 0.8194740686761226,
     "alpha": 1.5707963267948966,
     "rectified_grid_angle": 1.5707963267948966,
@@ -793,6 +796,7 @@
     "x0": 600000,
     "y0": 200000,
     "longc": 0.12984522414316146,
+    "long0": 0.12984522414316146,
     "lat0": 0.8194740686761218,
     "alpha": 1.5707963267948966,
     "rectified_grid_angle": 1.5707963267948966,
@@ -929,6 +933,7 @@
     "x0": 804671,
     "y0": 0,
     "longc": 1.784599160164202,
+    "long0": 1.784599160164202,
     "lat0": 0.06981317007977318,
     "alpha": 5.637863717220397,
     "rectified_grid_angle": 5.639684198507691,
@@ -1093,6 +1098,7 @@
     "x0": 804671,
     "y0": 0,
     "longc": 1.784599160164202,
+    "long0": 1.784599160164202,
     "lat0": 0.06981317007977318,
     "alpha": 5.637863717220403,
     "rectified_grid_angle": 5.63968419850769,
diff --git a/util.js b/util.js
index e6f2d1d..b5220c7 100644
--- a/util.js
+++ b/util.js
@@ -8,8 +8,8 @@ export function applyProjectionDefaults(wkt) {
   // Normalize projName for WKT2 compatibility
   const normalizedProjName = (wkt.projName || '').toLowerCase().replace(/_/g, ' ');
 
-  if (!wkt.long0 && wkt.longc && (normalizedProjName === 'albers conic equal area' || normalizedProjName === 'lambert azimuthal equal area')) {
-    wkt.long0 = wkt.longc;
+  if (wkt.long0 === undefined && wkt.longc !== undefined) {
+    wkt.long0 = wkt.longc; // keep in the projection's native prime meridian frame
   }
   if (!wkt.lat_ts && wkt.lat1 && (normalizedProjName === 'stereographic south pole' || normalizedProjName === 'polar stereographic (variant b)')) {
     wkt.lat0 = d2r(wkt.lat1 > 0 ? 90 : -90);