From 60312ddf56c7179d28b57c2bd1ee887f813c66d9 Mon Sep 17 00:00:00 2001
From: Leonard Hecker <lhecker@microsoft.com>
Date: Wed, 13 Oct 2021 01:06:50 +0200
Subject: [PATCH] Replace exceptions with HRESULTs

---
 src/terminal/parser/OutputStateMachineEngine.cpp |  7 +------
 src/terminal/parser/base64.cpp                   | 13 ++++++++-----
 src/terminal/parser/base64.hpp                   |  2 +-
 3 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/src/terminal/parser/OutputStateMachineEngine.cpp b/src/terminal/parser/OutputStateMachineEngine.cpp
index 71d8752c0c8..9695efcc865 100644
--- a/src/terminal/parser/OutputStateMachineEngine.cpp
+++ b/src/terminal/parser/OutputStateMachineEngine.cpp
@@ -1112,12 +1112,7 @@ bool OutputStateMachineEngine::_GetOscSetClipboard(const std::wstring_view strin
         }
         else
         {
-            try
-            {
-                Base64::Decode(substr, content);
-                return true;
-            }
-            CATCH_LOG()
+            LOG_IF_FAILED(Base64::Decode(substr, content));
         }
     }
 
diff --git a/src/terminal/parser/base64.cpp b/src/terminal/parser/base64.cpp
index 38c1c1e8757..499be69d9ea 100644
--- a/src/terminal/parser/base64.cpp
+++ b/src/terminal/parser/base64.cpp
@@ -4,6 +4,9 @@
 #include "precomp.h"
 #include "base64.hpp"
 
+// Regarding C4297: I didn't want to handle OOM errors. There's no reasonable mode
+// of operation for this application without the ability to allocate memory anyways.
+#pragma warning(disable : 4297) // '...': function assumed not to throw an exception but does
 #pragma warning(disable : 26446) // Prefer to use gsl::at() instead of unchecked subscript operator (bounds.4).
 #pragma warning(disable : 26481) // Don't use pointer arithmetic. Use span instead (bounds.1).
 #pragma warning(disable : 26482) // Only index into arrays using constant expressions (bounds.2).
@@ -30,7 +33,7 @@ static constexpr uint8_t decodeTable[128] = {
 // * Doesn't support whitespace and will throw an exception for such strings.
 // * Doesn't validate the number of trailing "=". Those are basically ignored.
 //   Strings like "YQ===" will be accepted as valid input and simply result in "a".
-void Base64::Decode(const std::wstring_view& src, std::wstring& dst)
+HRESULT Base64::Decode(const std::wstring_view& src, std::wstring& dst) noexcept
 {
     std::string result;
     result.resize(((src.size() + 3) / 4) * 3);
@@ -39,7 +42,7 @@ void Base64::Decode(const std::wstring_view& src, std::wstring& dst)
     // The remaining code in this function ensures not to read from in if src.empty().
 #pragma warning(suppress : 26429) // Symbol 'in' is never tested for nullness, it can be marked as not_null (f.23).
     auto in = src.data();
-    auto inEnd = in + src.size();
+    const auto inEnd = in + src.size();
     // Sometimes in programming you have to ask yourself what the right offset for a pointer is.
     // Is 4 enough? Certainly not. 6 on the other hand is just way too much. Clearly 5 is just right.
     //
@@ -144,12 +147,12 @@ void Base64::Decode(const std::wstring_view& src, std::wstring& dst)
             break;
         }
     }
-    
+
     if (error)
     {
-        throw std::runtime_error("invalid base64");
+        return HRESULT_FROM_WIN32(ERROR_INVALID_DATA);
     }
 
     result.resize(out - outBeg);
-    THROW_IF_FAILED(til::u8u16(result, dst));
+    return til::u8u16(result, dst);
 }
diff --git a/src/terminal/parser/base64.hpp b/src/terminal/parser/base64.hpp
index 5ad7b714f62..da8f22ec509 100644
--- a/src/terminal/parser/base64.hpp
+++ b/src/terminal/parser/base64.hpp
@@ -16,6 +16,6 @@ namespace Microsoft::Console::VirtualTerminal
     class Base64
     {
     public:
-        static void Decode(const std::wstring_view& src, std::wstring& dst);
+        static HRESULT Decode(const std::wstring_view& src, std::wstring& dst) noexcept;
     };
 }