From ff55b74bce98276a579fe3dc3ecae97144bc89a3 Mon Sep 17 00:00:00 2001
From: Sean Arms <67096+lesserwhirls@users.noreply.github.com>
Date: Tue, 14 Jul 2026 16:22:19 -0600
Subject: [PATCH] xpublish DAP2 implementation compatibility

In the xpublish implementation of the DAP2 das response, Not a Number
values for attributes are represented by the string nan. However, in
Java and other languages, the string representation is NaN, and thus
netCDF-Java fails to parse the value.

Fixes unidata/netcdf-java#1581
---
 opendap/src/main/java/ucar/nc2/dods/DODSAttribute.java | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/opendap/src/main/java/ucar/nc2/dods/DODSAttribute.java b/opendap/src/main/java/ucar/nc2/dods/DODSAttribute.java
index 0394f329ce..0f670c97d8 100644
--- a/opendap/src/main/java/ucar/nc2/dods/DODSAttribute.java
+++ b/opendap/src/main/java/ucar/nc2/dods/DODSAttribute.java
@@ -75,7 +75,14 @@ public DODSAttribute(String dodsName, opendap.dap.Attribute att) {
         data = Array.factory(ncType, new int[] {nvals});
         Index ima = data.getIndex();
         for (int i = 0; i < nvals; i++) {
-          double dval = Double.parseDouble(vals[i]);
+          double dval;
+          try {
+            dval = Double.parseDouble(vals[i]);
+          } catch (NumberFormatException e) {
+            // could be a python, rust (perhaps others) based server, in which case the string representation of NaN is
+            // nan
+            dval = Double.parseDouble(vals[i].replace("nan", "NaN"));
+          }
           data.setDouble(ima.set(i), dval);
         }
       } catch (NumberFormatException e) {