Created attachment 144105 [details]
Test program to reproduce the error.

While working on some OpenGL tutorials, I found that on my computer with Intel graphics, the fragment shader has problems - colours were coming out incorrect at first (works fine on my RX580).  When I tried to simplify the shader to narrow down the cause, the program started crashing during compilation of the shader with the error:

   corrupted size vs. prev_size
   Aborted (core dumped)

I compiled a debug version of Mesa (19.0.3) and got the following stack trace of the crash:

[kmshanah@cable test2]$ gdb ./lighting
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Reading symbols from ./lighting...done.
(gdb) run
Starting program: /home/kmshanah/projects/sdl/test2/lighting 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[New Thread 0x7ffff4e81700 (LWP 12031)]
malloc(): invalid size (unsorted)

Thread 1 "lighting" received signal SIGABRT, Aborted.
0x00007ffff75af82f in raise () from /usr/lib/libc.so.6
(gdb) bt
#0  0x00007ffff75af82f in raise () from /usr/lib/libc.so.6
#1  0x00007ffff759a672 in abort () from /usr/lib/libc.so.6
#2  0x00007ffff75f1e78 in __libc_message () from /usr/lib/libc.so.6
#3  0x00007ffff75f878a in malloc_printerr () from /usr/lib/libc.so.6
#4  0x00007ffff75fb4a4 in _int_malloc () from /usr/lib/libc.so.6
#5  0x00007ffff75fccda in malloc () from /usr/lib/libc.so.6
#6  0x00007ffff56907ce in ralloc_size (ctx=0x5555555bcbd0, size=size@entry=136) at ../mesa-19.0.3/src/util/ralloc.c:119
#7  0x00007ffff56908a9 in rzalloc_size (ctx=<optimized out>, size=size@entry=136) at ../mesa-19.0.3/src/util/ralloc.c:151
#8  0x00007ffff59a0a9d in nir_intrinsic_instr_create (shader=<optimized out>, op=nir_intrinsic_load_barycentric_pixel) at ../mesa-19.0.3/src/compiler/nir/nir.c:501
#9  0x00007ffff59ad3af in nir_load_barycentric (interp_mode=1, op=<optimized out>, build=0x7fffffffc508) at ../mesa-19.0.3/src/compiler/nir/nir_builder.h:1092
#10 lower_load (intrin=intrin@entry=0x555555c415c0, state=state@entry=0x7fffffffc500, vertex_index=0x0, var=0x555555c22da0, offset=0x555555c22ea0, component=0)
    at ../mesa-19.0.3/src/compiler/nir/nir_lower_io.c:227
#11 0x00007ffff59b357d in lower_interpolate_at (component=<optimized out>, offset=<optimized out>, var=<optimized out>, state=<optimized out>, intrin=<optimized out>)
    at ../mesa-19.0.3/src/compiler/nir/nir_lower_io.c:479
#12 nir_lower_io_block (block=0x555555c32150, state=0x7fffffffc500) at ../mesa-19.0.3/src/compiler/nir/nir_lower_io.c:510
#13 nir_lower_io_impl (options=(unknown: 0), type_size=0x7ffff5b9fe00 <brw::type_size_vec4(glsl_type const*)>, modes=nir_var_shader_in, impl=0x555555c279d0)
    at ../mesa-19.0.3/src/compiler/nir/nir_lower_io.c:554
#14 nir_lower_io (shader=shader@entry=0x5555555bcbd0, modes=modes@entry=nir_var_shader_in, type_size=0x7ffff5b9fe00 <brw::type_size_vec4(glsl_type const*)>, options=(unknown: 0))
    at ../mesa-19.0.3/src/compiler/nir/nir_lower_io.c:573
#15 0x00007ffff5b36f10 in brw_nir_lower_fs_inputs (nir=nir@entry=0x5555555bcbd0, devinfo=devinfo@entry=0x55555561b718, key=key@entry=0x7fffffffdf00)
    at ../mesa-19.0.3/src/intel/compiler/brw_nir.c:455
#16 0x00007ffff5af2754 in brw_compile_fs (compiler=0x55555561d7b0, log_data=log_data@entry=0x5555558065b0, mem_ctx=mem_ctx@entry=0x555555c21fd0, key=key@entry=0x7fffffffdf00, 
    prog_data=prog_data@entry=0x7fffffffdcb0, shader=shader@entry=0x5555555bcbd0, prog=0x555555c29d60, shader_time_index8=-1, shader_time_index16=-1, shader_time_index32=-1, 
    allow_spilling=true, use_rep_send=false, vue_map=0x7fffffffdfb0, error_str=0x7fffffffdca8) at ../mesa-19.0.3/src/intel/compiler/brw_fs.cpp:7604
#17 0x00007ffff55f9778 in brw_codegen_wm_prog (brw=brw@entry=0x5555558065b0, fp=fp@entry=0x555555c29d60, key=key@entry=0x7fffffffdf00, vue_map=0x7fffffffdfb0)
    at ../mesa-19.0.3/src/mesa/drivers/dri/i965/brw_wm.c:184
#18 0x00007ffff55fb746 in brw_fs_precompile (ctx=ctx@entry=0x5555558065b0, prog=0x555555c29d60) at ../mesa-19.0.3/src/mesa/drivers/dri/i965/brw_wm.c:689
#19 0x00007ffff55e40db in brw_shader_precompile (sh_prog=0x555555847e60, ctx=0x5555558065b0) at ../mesa-19.0.3/src/mesa/drivers/dri/i965/brw_link.cpp:56
#20 brw_link_shader (ctx=0x5555558065b0, shProg=0x555555847e60) at ../mesa-19.0.3/src/mesa/drivers/dri/i965/brw_link.cpp:375
#21 0x00007ffff58297da in _mesa_glsl_link_shader (ctx=ctx@entry=0x5555558065b0, prog=prog@entry=0x555555847e60) at ../mesa-19.0.3/src/mesa/program/ir_to_mesa.cpp:3174
#22 0x00007ffff5723e3a in link_program (no_error=<optimized out>, shProg=<optimized out>, ctx=<optimized out>) at ../mesa-19.0.3/src/mesa/main/shaderapi.c:1206
#23 link_program_error (shProg=0x555555847e60, ctx=0x5555558065b0) at ../mesa-19.0.3/src/mesa/main/shaderapi.c:1286
#24 link_program_error (ctx=0x5555558065b0, shProg=0x555555847e60) at ../mesa-19.0.3/src/mesa/main/shaderapi.c:1284
#25 0x0000555555556884 in load_shader (vertexPath=0x555555575f2e "lighting.vs", fragmentPath=0x555555575f22 "lighting.fs", result=0x7fffffffe260) at shader.c:99
#26 0x0000555555572d16 in initGL () at lighting.c:222
#27 0x0000555555572cb2 in init () at lighting.c:208
#28 0x0000555555573f40 in main (argc=1, args=0x7fffffffe878) at lighting.c:544

glxinfo gives the following driver info:

    Vendor: Intel Open Source Technology Center (0x8086)
    Device: Mesa DRI Intel(R) HD Graphics 515 (Skylake GT2)  (0x191e)
    Version: 19.0.3
    Accelerated: yes
    Video memory: 3072MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2

I will attach my small test program.