From 4428fbcf1ee70da4d82e74e25c039eb209770aa6 Mon Sep 17 00:00:00 2001
From: Bernhard Kirchen <schlimmchen@posteo.net>
Date: Tue, 29 Oct 2024 10:00:04 +0100
Subject: [PATCH] Fix: skip BOM in JSON files (pin_mapping and config)

---
 src/Configuration.cpp | 7 +++++++
 src/PinMapping.cpp    | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/src/Configuration.cpp b/src/Configuration.cpp
index db47d9c8a..aefde2c7a 100644
--- a/src/Configuration.cpp
+++ b/src/Configuration.cpp
@@ -160,6 +160,13 @@ bool ConfigurationClass::read()
 {
     File f = LittleFS.open(CONFIG_FILENAME, "r", false);
 
+    // skip Byte Order Mask (BOM). valid JSON docs always start with '{' or '['.
+    while (f.available() > 0) {
+        int c = f.peek();
+        if (c == '{' || c == '[') { break; }
+        f.read();
+    }
+
     JsonDocument doc;
 
     // Deserialize the JSON document
diff --git a/src/PinMapping.cpp b/src/PinMapping.cpp
index bd5ea9952..52fff79f7 100644
--- a/src/PinMapping.cpp
+++ b/src/PinMapping.cpp
@@ -199,6 +199,13 @@ bool PinMappingClass::init(const String& deviceMapping)
         return false;
     }
 
+    // skip Byte Order Mask (BOM). valid JSON docs always start with '{' or '['.
+    while (f.available() > 0) {
+        int c = f.peek();
+        if (c == '{' || c == '[') { break; }
+        f.read();
+    }
+
     JsonDocument doc;
     // Deserialize the JSON document
     DeserializationError error = deserializeJson(doc, f);