From 9f37ad360ea1c32162f0cc1799b1b292594fc771 Mon Sep 17 00:00:00 2001
From: Steve Urquhart <steve.urquhart@ntd.nintendo.com>
Date: Fri, 9 Feb 2024 15:14:12 -0500
Subject: [PATCH] Support files with UTF8BOM character

---
 StandAlone/StandAlone.cpp         | 14 ++++++++++++++
 Test/UTF8BOM.vert                 | 11 +++++++++++
 Test/baseResults/UTF8BOM.vert.out |  1 +
 Test/runtests                     |  7 +++++++
 4 files changed, 33 insertions(+)
 create mode 100644 Test/UTF8BOM.vert
 create mode 100644 Test/baseResults/UTF8BOM.vert.out

diff --git a/StandAlone/StandAlone.cpp b/StandAlone/StandAlone.cpp
index 9cccdf6f..ac967f2b 100644
--- a/StandAlone/StandAlone.cpp
+++ b/StandAlone/StandAlone.cpp
@@ -2167,6 +2167,20 @@ char* ReadFileData(const char* fileName)
 
     fseek(in, 0, SEEK_SET);
 
+    if (count > 3) {
+        unsigned char head[3];
+        if (fread(head, 1, 3, in) == 3) {
+            if (head[0] == 0xef && head[1] == 0xbb && head[2] == 0xbf) {
+                // skip BOM
+                count -= 3;
+            } else {
+                fseek(in, 0, SEEK_SET);
+            }
+        } else {
+            Error("can't read input file");
+        }
+    }
+
     char* return_data = (char*)malloc(count + 1);  // freed in FreeFileData()
     if ((int)fread(return_data, 1, count, in) != count) {
         free(return_data);
diff --git a/Test/UTF8BOM.vert b/Test/UTF8BOM.vert
new file mode 100644
index 00000000..357cc54b
--- /dev/null
+++ b/Test/UTF8BOM.vert
@@ -0,0 +1,11 @@
+/*
+
+glslangValidator.exe --glsl-version 410 -V -S vert -o UTF8BOM.vert.out UTF8BOM.vert
+
+*/
+
+#version 110
+
+void main()
+{
+}
diff --git a/Test/baseResults/UTF8BOM.vert.out b/Test/baseResults/UTF8BOM.vert.out
new file mode 100644
index 00000000..19db13f6
--- /dev/null
+++ b/Test/baseResults/UTF8BOM.vert.out
@@ -0,0 +1 @@
+UTF8BOM.vert
diff --git a/Test/runtests b/Test/runtests
index d3c1646e..00c2babd 100755
--- a/Test/runtests
+++ b/Test/runtests
@@ -348,6 +348,13 @@ diff -b $BASEDIR/enhanced.7.link.out "$TARGETDIR/enhanced.7.link.out" || HASERRO
 run --enhanced-msgs -V --target-env vulkan1.2 --amb --aml spv.textureError.frag > "$TARGETDIR/spv.textureError.frag.out"
 diff -b $BASEDIR/spv.textureError.frag.out "$TARGETDIR/spv.textureError.frag.out" || HASERROR=1
 
+#
+# Test UTF8BOM
+#
+echo "Testing UTF8BOM"
+run --glsl-version 410 -V -S vert UTF8BOM.vert > $TARGETDIR/UTF8BOM.vert.out
+diff -b $BASEDIR/UTF8BOM.vert.out $TARGETDIR/UTF8BOM.vert.out || HASERROR=1
+
 #
 # Final checking
 #