From ff2c4942dd4ecd51d4802e794843772a89345a76 Mon Sep 17 00:00:00 2001
From: Laurent Garnier <lg.hc@free.fr>
Date: Wed, 5 Jul 2023 19:27:00 +0200
Subject: [PATCH] Avoid warning log introduced by PR #3644

Fix openhab/openhab-webui#1951

Signed-off-by: Laurent Garnier <lg.hc@free.fr>
---
 .../ui/internal/items/ItemUIRegistryImpl.java | 35 ++++++++++---------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/bundles/org.openhab.core.ui/src/main/java/org/openhab/core/ui/internal/items/ItemUIRegistryImpl.java b/bundles/org.openhab.core.ui/src/main/java/org/openhab/core/ui/internal/items/ItemUIRegistryImpl.java
index d5a69469427..1862082e2e8 100644
--- a/bundles/org.openhab.core.ui/src/main/java/org/openhab/core/ui/internal/items/ItemUIRegistryImpl.java
+++ b/bundles/org.openhab.core.ui/src/main/java/org/openhab/core/ui/internal/items/ItemUIRegistryImpl.java
@@ -1373,26 +1373,29 @@ public void removeRegistryHook(RegistryHook<Item> hook) {
 
     @Override
     public @Nullable String getUnitForWidget(Widget w) {
-        try {
-            Item item = getItem(w.getItem());
+        String itemName = w.getItem();
+        if (itemName != null) {
+            try {
+                Item item = getItem(itemName);
 
-            // we require the item to define a dimension, otherwise no unit will be reported to the UIs.
-            if (item instanceof NumberItem numberItem && numberItem.getDimension() != null) {
-                String pattern = getFormatPattern(w);
-                if (pattern == null || pattern.isBlank()) {
-                    // if no Label was assigned to the Widget we fallback to the items unit
-                    return numberItem.getUnitSymbol();
-                }
+                // we require the item to define a dimension, otherwise no unit will be reported to the UIs.
+                if (item instanceof NumberItem numberItem && numberItem.getDimension() != null) {
+                    String pattern = getFormatPattern(w);
+                    if (pattern == null || pattern.isBlank()) {
+                        // if no Label was assigned to the Widget we fallback to the items unit
+                        return numberItem.getUnitSymbol();
+                    }
 
-                String unit = getUnitFromPattern(pattern);
-                if (!UnitUtils.UNIT_PLACEHOLDER.equals(unit)) {
-                    return unit;
-                }
+                    String unit = getUnitFromPattern(pattern);
+                    if (!UnitUtils.UNIT_PLACEHOLDER.equals(unit)) {
+                        return unit;
+                    }
 
-                return numberItem.getUnitSymbol();
+                    return numberItem.getUnitSymbol();
+                }
+            } catch (ItemNotFoundException e) {
+                logger.warn("Failed to retrieve item during widget rendering, item does not exist: {}", e.getMessage());
             }
-        } catch (ItemNotFoundException e) {
-            logger.warn("Failed to retrieve item during widget rendering, item does not exist: {}", e.getMessage());
         }
 
         return "";