Global const inlining breaks after a block scope using the same id

[Alexander Kraus]

The shader

#version 450

out vec4 out_color;

const float s = 1.;

float a(float s) {
    s = 2.;
    return s;
}

void main() {
    out_color = vec4(s, s, a(s), s);
}

gets minified to

#version 450
out vec4 m;
float s(float s) { return 2.; }
void main() { m = vec4(s, s, s(s), s); }

Which produces the following compiler error:

C:\Users\NR4>Downloads\glslang-master-windows-Release\bin\glslangValidator.exe minbug.min.frag
minbug.min.frag
ERROR: 0:2: 's' : undeclared identifier
ERROR: 0:2: '' : compilation terminated
ERROR: 2 compilation errors.  No code generated.

[Alexander Kraus]

I worked around this by avoiding globally defined ids in any and all block scopes.

[Laurent Le Brun]

The code defines two s (one global, the other is a parameter). A workaround is to rename one of them.

The line s = 2. seems to cause a bug in the inlining mechanism. This seems to happen only when s is a function argument (not if it's a local variable).