Test that overly long entries in DL_LOAD_PATH don't result in segfault

stdlib/Libdl/test/runtests.jl

@@ -222,13 +222,16 @@ let dl = C_NULL
  @test_skip !Libdl.dlclose(dl) # Syscall doesn't fail on Win32
 end
 
-# test @executable_path expansion
+# test DL_LOAD_PATH handling and @executable_path expansion
 mktempdir() do dir
  # Create a `libdcalltest` in a directory that is not on our load path
  src_path = joinpath(private_libdir, "libccalltest.$(Libdl.dlext)")
  dst_path = joinpath(dir, "libdcalltest.$(Libdl.dlext)")
  cp(src_path, dst_path)
 
+ # Add an absurdly long entry to the load path to verify it doesn't lead to a buffer overflow
+ push!(Base.DL_LOAD_PATH, joinpath(dir, join(rand('a':'z', 10000))))
+
  # Add this temporary directory to our load path, using `@executable_path` to do so.
  push!(Base.DL_LOAD_PATH, joinpath("@executable_path", relpath(dir, Sys.BINDIR)))
 
@@ -243,6 +246,23 @@ mktempdir() do dir
  fptr = Libdl.dlsym_e(dl, :foo)
  @test fptr == C_NULL
  end
+
+ # Now use the absolute path
+ empty!(Base.DL_LOAD_PATH)
+ push!(Base.DL_LOAD_PATH, joinpath(dir, join(rand('a':'z', 10000))))
+ push!(Base.DL_LOAD_PATH, dir)
+
+ # Test that we can now open that file
+ Libdl.dlopen("libdcalltest") do dl
+ fptr = Libdl.dlsym(dl, :set_verbose)
+ @test fptr !== nothing
+ @test_throws ErrorException Libdl.dlsym(dl, :foo)
+
+ fptr = Libdl.dlsym_e(dl, :set_verbose)
+ @test fptr != C_NULL
+ fptr = Libdl.dlsym_e(dl, :foo)
+ @test fptr == C_NULL
+ end
 end
 
 end