Windows 8.1 64-bit and GeForce GT 735 M (Sony VAIO SVF 15A)
Broken: 2.71 9337574, (official 2) and 2.71 5588e45 (latest Windows x64 buildbot version)
Worked: (I don't know of any)
When attempting to use an Open Shading Language script that loads more than two textures, blender crashes immediately upon beginning a render (viewport or not). The OSL shader will successfully compile, but attempting to use it causes a crash.
Crashes only occur if more than two textures contribute to the output of the script; if a texture is included in the code but not used, the script can be used without crashing.
The problem does not appear to be the combined size of the textures; a single 868 kb texture loads perfectly while three 3.63 kb textures cause a crash.
The problem does not appear to be a limited number of textures accessible by all OSL scripts in a .blend file that are contributing to a material; using multiple scripts and choosing different textures to output does not cause a crash, so long as no more than two textures are used by any individual script.
Exact steps for others to reproduce the error
A .blend file containing an example of such a problematic script is included; the .zip file contains the Textures folder that is referred to in the script. To get the OSL script in the .blend file to run without modification, extract the .zip file so that 0.png, 1.png, and 2.png are located in C:\Textures\. But the script node has a field for entering the data path, which can be changed to point to any directory you'd like, so you don't need to put them where I did in my example.
An example OSL script should be open in a text window when the .blend file is opened: the script is included below, with an additional comment describing what to change to cause the crash:
string Folder = "C:/Textures/", output color Stamp = 0)
float x1 = P; float y1 = -P; color Number = texture(concat(Folder,"0.png"),x1,y1); color Number1 = texture(concat(Folder,"1.png"),x1-1.0,y1); color Number2 = texture(concat(Folder,"2.png"),x1-2.0,y1); color total = Number+Number1+0*Number2;
// Change the above line to "color total = Number+Number1+Number2;" (remove the 0*) and click "script node update" and then try a viewport render in the 3D view window to the right of the text window. For me, Blender crashes.
Stamp = total;