#include does not handle absolute paths correctly

[Ravbug]

The following shader does not compile, despite the included file existing:

#include "C:\users\Admin\Desktop\file.glsl"

void main(){}

This is because quoted includes get passed to readLocalPath, which assumes the path is local and transforms it before trying to read it:

glslang/StandAlone/DirStackFileIncluder.h

Lines 103 to 124 in 1cad045

	virtual IncludeResult* readLocalPath(const char* headerName, const char* includerName, int depth)
	{
	// Discard popped include directories, and
	// initialize when at parse-time first level.
	directoryStack.resize(depth + externalLocalDirectoryCount);
	if (depth == 1)
	directoryStack.back() = getDirectory(includerName);
	// Find a directory that works, using a reverse search of the include stack.
	for (auto it = directoryStack.rbegin(); it != directoryStack.rend(); ++it) {
	std::string path = *it + '/' + headerName;
	std::replace(path.begin(), path.end(), '\\', '/');
	std::ifstream file(path, std::ios_base::binary | std::ios_base::ate);
	if (file) {
	directoryStack.push_back(getDirectory(path));
	includedFiles.insert(path);
	return newIncludeResult(path, file, (int)file.tellg());
	}
	}
	return nullptr;
	}

I fixed this in my copy by changing readLocalPath to check headerName as-is, in case it's an absolute path, before transforming it as a local path:

virtual IncludeResult* readLocalPath(const char* headerName, const char* includerName, int depth)
{
    // first check for absolute paths:
    std::ifstream file(headerName, std::ios_base::binary | std::ios_base::ate);
    if (file) {
        directoryStack.push_back(getDirectory(headerName));
        includedFiles.insert(headerName);
        return newIncludeResult(headerName, file, (int)file.tellg());
    }

    // Discard popped include directories, and 
   // ...
    ```