refactor(git): URI scheme is now a git revspec, loaded via cat-file -p

lua/git/object.lua

@@ -87,11 +87,14 @@ end
 ---@param ref string  the commit ref the blob represents (e.g. `<sha>` or `<sha>^`)
 ---@return integer
 local function blob_buf(worktree, blob, path, ref)
-    local name = "git://" .. ref .. "//" .. path
+    local revspec = ref .. ":" .. path
     if is_zero(blob) then
-        return diff.empty_buf({ name = name, bufhidden = "hide" })
+        return diff.empty_buf({
+            name = "git://" .. revspec,
+            bufhidden = "hide",
+        })
     end
-    return diff.git_show_buf(worktree, ref, path)
+    return diff.git_show_buf(worktree, revspec)
 end
 
 ---@param worktree string
@@ -142,7 +145,7 @@ end
 function M.open_commit(worktree, ref, opts)
     local split = opts and opts.split
     local sha = repo.rev_parse(worktree, ref, true) or ref
-    local name = "git://" .. sha .. "//"
+    local name = "git://" .. sha
     local existing = vim.fn.bufnr(name)
     if existing ~= -1 and vim.api.nvim_buf_is_loaded(existing) then
         if split == false then
@@ -218,7 +221,7 @@ function M.open_object(worktree, ref, opts)
 
     local split = opts and opts.split
     local sha = repo.rev_parse(worktree, ref, true) or ref
-    local name = "git://" .. sha .. "//"
+    local name = "git://" .. sha
     local existing = vim.fn.bufnr(name)
     if existing ~= -1 and vim.api.nvim_buf_is_loaded(existing) then
         if split == false then
@@ -279,7 +282,8 @@ function M.open_under_cursor()
         line:match("^%d+ (%w+) (%x+)\t(.+)$")
     if entry_sha then
         if entry_type == "blob" then
-            local buf = diff.git_show_buf(ctx.worktree, ctx.ref, entry_name)
+            local buf =
+                diff.git_show_buf(ctx.worktree, ctx.ref .. ":" .. entry_name)
             vim.cmd.normal({ "m'", bang = true })
             vim.api.nvim_set_current_buf(buf)
         else