Fix issue with Git Credential Manager for Windows (JuliaLang#30195)

- Ignores additional whitespace when reading in credentials.
- Warn when encountering unknown attributes. Should allow for more
  graceful failures in the future if the protocol is extended.

stdlib/LibGit2/src/gitcredential.jl

@@ -1,5 +1,7 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
+const GIT_CRED_ATTRIBUTES = ("protocol", "host", "path", "username", "password", "url")
+
 """
  GitCredential
 
@@ -111,16 +113,19 @@ function Base.read!(io::IO, cred::GitCredential)
  else
  value = readuntil(io, '\n')
  end
+
  if key == "url"
  # Any components which are missing from the URL will be set to empty
  # https://git-scm.com/docs/git-credential#git-credential-codeurlcode
  Base.shred!(parse(GitCredential, value)) do urlcred
  copy!(cred, urlcred)
  end
- else
+ elseif key in GIT_CRED_ATTRIBUTES
  field = getproperty(cred, Symbol(key))
  field !== nothing && Symbol(key) == :password && Base.shred!(field)
  setproperty!(cred, Symbol(key), value)
+ elseif !all(isspace, key)
+ @warn "Unknown git credential attribute found: $(repr(key))"
  end
  end
 

stdlib/LibGit2/test/libgit2.jl

@@ -462,6 +462,45 @@ end
  Base.shred!(expected_cred)
  end
 
+ @testset "extra newline" begin
+ # The "Git for Windows" installer will also install the "Git Credential Manager for
+ # Windows" (https://github.com/Microsoft/Git-Credential-Manager-for-Windows) (also
+ # known as "manager" in the .gitconfig files). This credential manager returns an
+ # additional newline when returning the results.
+ str = """
+ protocol=https
+ host=example.com
+ path=
+ username=bob
+ password=*****
+
+ """
+ expected_cred = LibGit2.GitCredential("https", "example.com", "", "bob", "*****")
+
+ cred = read!(IOBuffer(str), LibGit2.GitCredential())
+ @test cred == expected_cred
+ @test sprint(write, cred) * "\n" == str
+ Base.shred!(cred)
+ Base.shred!(expected_cred)
+ end
+
+ @testset "unknown attribute" begin
+ str = """
+ protocol=https
+ host=example.com
+ attribute=value
+ username=bob
+ password=*****
+ """
+ expected_cred = LibGit2.GitCredential("https", "example.com", nothing, "bob", "*****")
+ expected_log = (:warn, "Unknown git credential attribute found: \"attribute\"")
+
+ cred = @test_logs expected_log read!(IOBuffer(str), LibGit2.GitCredential())
+ @test cred == expected_cred
+ Base.shred!(cred)
+ Base.shred!(expected_cred)
+ end
+
  @testset "use http path" begin
  cred = LibGit2.GitCredential("https", "example.com", "dir/file", "alice", "*****")
  expected = """