Fix the latent tail from the Common/Core review

Buffer::PeekAll resized the destination and then appended, so it returned twice the
data with zeros in front. No callers today.

The assert dialog's caption was a function-local static, so it froze at whichever
kind of assert fired first in the session - a later Critical Assert would still be
titled 'Debug Assert'. Made it a plain const char *.

containsNoCase passed a possibly-negative char to std::toupper, which is UB for
anything but EOF; non-ASCII bytes get here from ELF symbol names.

ApplyDeadzoneXY's circular path lacked the deadzone >= 0.99f guard its own sibling
ApplyDeadzoneAxis has one function above, so it divided by ~0.

Common/Buffer.cpp

@@ -136,7 +136,9 @@ bool Buffer::FlushToFile(const Path &filename, bool clear) {
 }
 
 void Buffer::PeekAll(std::string *dest) {
-	dest->resize(data_.size());
+	// resize() here would leave that many zero bytes in front of the appended data.
+	dest->clear();
+	dest->reserve(data_.size());
 	data_.iterate_blocks(([dest](const char *blockData, size_t blockSize) {
 		dest->append(blockData, blockSize);
 		return true;

Common/Log.cpp

@@ -136,8 +136,9 @@ bool HandleAssert(bool isDebugAssert, const char *function, const char *file, in
 		const char *threadName = GetCurrentThreadName();
 		OutputDebugStringA(formatted);
 		printf("%s\n", formatted);
-		static const std::string caption = isDebugAssert ? "Debug Assert" : "Critical Assert";
-		std::wstring wcaption = ConvertUTF8ToWString(caption + " " + (threadName ? threadName : "(unknown thread)"));
+		// Not static - it'd freeze at whatever the first assert in the session was.
+		const char *caption = isDebugAssert ? "Debug Assert" : "Critical Assert";
+		std::wstring wcaption = ConvertUTF8ToWString(std::string(caption) + " " + (threadName ? threadName : "(unknown thread)"));
 		switch (MessageBox(g_dialogParent, ConvertUTF8ToWString(text).c_str(), wcaption.c_str(), msgBoxStyle)) {
 		case IDYES:
 			return true;

Common/StringUtils.cpp

@@ -86,7 +86,11 @@ long parseLong(std::string s) {
 }
 
 bool containsNoCase(std::string_view haystack, std::string_view needle) {
-	auto pred = [](char ch1, char ch2) { return std::toupper(ch1) == std::toupper(ch2); };
+	// toupper is UB for negative values other than EOF, and char is signed here - non-ASCII bytes
+	// reach this from e.g. ELF symbol names.
+	auto pred = [](char ch1, char ch2) {
+		return std::toupper((unsigned char)ch1) == std::toupper((unsigned char)ch2);
+	};
 	auto found = std::search(haystack.begin(), haystack.end(), needle.begin(), needle.end(), pred);
 	return found != haystack.end();
 }

Core/TiltEventProcessor.cpp

@@ -55,6 +55,13 @@ inline float ApplyDeadzoneAxis(float x, float deadzone) {
 
 inline void ApplyDeadzoneXY(float x, float y, float *adjustedX, float *adjustedY, float deadzone, bool circular) {
 	if (circular) {
+		if (deadzone >= 0.99f) {
+			// Same guard as ApplyDeadzoneAxis - without it the factor below divides by ~0.
+			*adjustedX = x;
+			*adjustedY = y;
+			return;
+		}
+
 		if (x == 0.0f && y == 0.0f) {
 			*adjustedX = 0.0f;
 			*adjustedY = 0.0f;