A long expression in a GLSL shader will crash Mesa, the crash occurs after parsing in generating the HIR from the AST.
Attached is a vertex shader with such a long expression (10,000 add terms).
The bug issue is that although such a shader is not to be found in "real" applications, a malicious website can use WebGL to crash Mesa which would likely crash the browser.
Created attachment 89138 [details]
Fragment shader of program.
Pushed "back" at the wrong time and submitted the bug twice, apologies.
*** This bug has been marked as a duplicate of bug 71574 ***