Fix zencore bugs and propagate content type through IoBufferBuilder (#783)

- Add missing includes in hashutils.h (`<cstddef>`, `<type_traits>`)
- Add `ZenContentType` parameter to all `IoBufferBuilder` factory methods so content type is set at buffer creation time
- Fix null dereference in `SharedBuffer::GetFileReference()` when buffer is null
- Fix out-of-bounds read in trace command-line argument parsing when arg length exactly matches option length
- Add unit tests for 32-bit `CountLeadingZeros`

1 files changed, 10 insertions, 3 deletions

diff --git a/src/zencore/trace.cpp b/src/zencore/trace.cpp
index 87035554f..a026974c0 100644
--- a/src/zencore/trace.cpp
+++ b/src/zencore/trace.cpp
@@ -165,10 +165,17 @@ GetTraceOptionsFromCommandline(TraceOptions& OutOptions)
 	auto MatchesArg = [](std::string_view Option, std::string_view Arg) -> std::optional<std::string_view> {
 		if (Arg.starts_with(Option))
 		{
-			std::string_view::value_type DelimChar = Arg[Option.length()];
-			if (DelimChar == ' ' || DelimChar == '=')
+			if (Arg.length() > Option.length())
 			{
-				return Arg.substr(Option.size() + 1);
+				std::string_view::value_type DelimChar = Arg[Option.length()];
+				if (DelimChar == ' ' || DelimChar == '=')
+				{
+					return Arg.substr(Option.size() + 1);
+				}
+			}
+			else
+			{
+				return ""sv;
 			}
 		}
 		return {};