git cas: only compute absolute path if not absolute already

... and in this way, continue to work correctly in the absence
of a current working directory.

2 files changed, 17 insertions, 3 deletions

diff --git a/src/buildtool/file_system/TARGETS b/src/buildtool/file_system/TARGETS
index 1af5dea8..26bb3933 100644
--- a/src/buildtool/file_system/TARGETS
+++ b/src/buildtool/file_system/TARGETS
@@ -57,6 +57,7 @@
   , "private-deps":
     [ ["src/buildtool/logging", "logging"]
     , ["src/utils/cpp", "hex_string"]
+    , ["src/utils/cpp", "path"]
     , ["", "libgit2"]
     ]
   }
diff --git a/src/buildtool/file_system/git_cas.cpp b/src/buildtool/file_system/git_cas.cpp
index f134a894..7bddf6b3 100644
--- a/src/buildtool/file_system/git_cas.cpp
+++ b/src/buildtool/file_system/git_cas.cpp
@@ -21,6 +21,7 @@
 #include "gsl/gsl"
 #include "src/buildtool/logging/logger.hpp"
 #include "src/utils/cpp/hex_string.hpp"
+#include "src/utils/cpp/path.hpp"
 
 #ifndef BOOTSTRAP_BUILD_TOOL
 
@@ -155,9 +156,21 @@ auto GitCAS::OpenODB(std::filesystem::path const& repo_path) noexcept -> bool {
         git_odb* odb_ptr{nullptr};
         git_repository_odb(&odb_ptr, repo);
         odb_.reset(odb_ptr);  // retain odb pointer
-        // set root
-        git_path_ = std::filesystem::weakly_canonical(std::filesystem::absolute(
-            std::filesystem::path(git_repository_path(repo))));
+                              // set root
+        std::filesystem::path git_path =
+            ToNormalPath(git_repository_path(repo));
+        if (not git_path.is_absolute()) {
+            try {
+                git_path = std::filesystem::absolute(git_path);
+            } catch (std::exception const& e) {
+                Logger::Log(LogLevel::Error,
+                            "Failed to obtain absolute path for {}: {}",
+                            git_path.string(),
+                            e.what());
+                return false;
+            }
+        }
+        git_path_ = git_path;
         // release resources
         git_repository_free(repo);
     }