From a47bbd0fdb639ac9674318baef289504a845ef5e Mon Sep 17 00:00:00 2001
From: Stefan Karpinski <stefan@karpinski.org>
Date: Fri, 4 Dec 2020 10:25:39 -0500
Subject: [PATCH] use a copy of GitTools with isexecutable fix

---
 Project.toml      |   3 +-
 test/git_tools.jl | 130 ++++++++++++++++++++++++++++++++++++++++++++++
 test/setup.jl     |   3 +-
 3 files changed, 133 insertions(+), 3 deletions(-)
 create mode 100644 test/git_tools.jl

diff --git a/Project.toml b/Project.toml
index c5acded..a16bc55 100644
--- a/Project.toml
+++ b/Project.toml
@@ -12,11 +12,10 @@ ArgTools = "1.1"
 julia = "1.3"
 
 [extras]
-Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 SimpleBufferStream = "777ac1f9-54b0-4bf8-805c-2214025038e7"
 Tar_jll = "9b64493d-8859-5bf3-93d7-7c32dd38186f"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Pkg", "Random", "Tar_jll", "Test", "SimpleBufferStream"]
+test = ["Random", "Tar_jll", "Test", "SimpleBufferStream"]
diff --git a/test/git_tools.jl b/test/git_tools.jl
new file mode 100644
index 0000000..dd09902
--- /dev/null
+++ b/test/git_tools.jl
@@ -0,0 +1,130 @@
+# copied from Pkg.jl/src/GitTools.jl
+
+module GitTools
+
+using SHA
+import Base: SHA1
+
+@enum GitMode mode_dir=0o040000 mode_normal=0o100644 mode_executable=0o100755 mode_symlink=0o120000 mode_submodule=0o160000
+Base.string(mode::GitMode) = string(UInt32(mode); base=8)
+Base.print(io::IO, mode::GitMode) = print(io, string(mode))
+
+function gitmode(path::AbstractString)
+    if islink(path)
+        return mode_symlink
+    elseif isdir(path)
+        return mode_dir
+    elseif Sys.isexecutable(path)
+        return mode_executable
+    else
+        return mode_normal
+    end
+end
+
+"""
+    blob_hash(HashType::Type, path::AbstractString)
+
+Calculate the git blob hash of a given path.
+"""
+function blob_hash(::Type{HashType}, path::AbstractString) where HashType
+    ctx = HashType()
+    if islink(path)
+        datalen = length(readlink(path))
+    else
+        datalen = filesize(path)
+    end
+
+    # First, the header
+    SHA.update!(ctx, Vector{UInt8}("blob $(datalen)\0"))
+
+    # Next, read data in in chunks of 4KB
+    buff = Vector{UInt8}(undef, 4*1024)
+
+    try
+        if islink(path)
+            update!(ctx, Vector{UInt8}(readlink(path)))
+        else
+            open(path, "r") do io
+                while !eof(io)
+                    num_read = readbytes!(io, buff)
+                    update!(ctx, buff, num_read)
+                end
+            end
+        end
+    catch e
+        if isa(e, InterruptException)
+            rethrow(e)
+        end
+        @warn("Unable to open $(path) for hashing; git-tree-sha1 likely suspect")
+    end
+
+    # Finish it off and return the digest!
+    return SHA.digest!(ctx)
+end
+blob_hash(path::AbstractString) = blob_hash(SHA1_CTX, path)
+
+"""
+    contains_files(root::AbstractString)
+
+Helper function to determine whether a directory contains files; e.g. it is a
+direct parent of a file or it contains some other directory that itself is a
+direct parent of a file. This is used to exclude directories from tree hashing.
+"""
+function contains_files(path::AbstractString)
+    st = lstat(path)
+    ispath(st) || throw(ArgumentError("non-existent path: $(repr(path))"))
+    isdir(st) || return true
+    for p in readdir(path)
+        contains_files(joinpath(path, p)) && return true
+    end
+    return false
+end
+
+
+"""
+    tree_hash(HashType::Type, root::AbstractString)
+
+Calculate the git tree hash of a given path.
+"""
+function tree_hash(::Type{HashType}, root::AbstractString) where HashType
+    entries = Tuple{String, Vector{UInt8}, GitMode}[]
+    for f in readdir(root)
+        # Skip `.git` directories
+        if f == ".git"
+            continue
+        end
+
+        filepath = abspath(root, f)
+        mode = gitmode(filepath)
+        if mode == mode_dir
+            # If this directory contains no files, then skip it
+            contains_files(filepath) || continue
+
+            # Otherwise, hash it up!
+            hash = tree_hash(HashType, filepath)
+        else
+            hash = blob_hash(HashType, filepath)
+        end
+        push!(entries, (f, hash, mode))
+    end
+
+    # Sort entries by name (with trailing slashes for directories)
+    sort!(entries, by = ((name, hash, mode),) -> mode == mode_dir ? name*"/" : name)
+
+    content_size = 0
+    for (n, h, m) in entries
+        content_size += ndigits(UInt32(m); base=8) + 1 + sizeof(n) + 1 + sizeof(h)
+    end
+
+    # Return the hash of these entries
+    ctx = HashType()
+    SHA.update!(ctx, Vector{UInt8}("tree $(content_size)\0"))
+    for (name, hash, mode) in entries
+        SHA.update!(ctx, Vector{UInt8}("$(mode) $(name)\0"))
+        SHA.update!(ctx, hash)
+    end
+    return SHA.digest!(ctx)
+end
+tree_hash(root::AbstractString) = tree_hash(SHA.SHA1_CTX, root)
+
+end # module
diff --git a/test/setup.jl b/test/setup.jl
index 31b9153..5d2f4e9 100644
--- a/test/setup.jl
+++ b/test/setup.jl
@@ -3,7 +3,8 @@ using Random
 using ArgTools
 
 import Tar
-import Pkg.GitTools
+
+include("git_tools.jl")
 
 const NON_STDLIB_TESTS = Main == @__MODULE__