feat(git): give every new git window a fresh jumplist

lua/git/log.lua

@@ -34,8 +34,32 @@ local function populate(buf)
     if not stdout then
         return
     end
+    local new_lines = util.split_lines(stdout)
+    local old_str = table.concat(
+        vim.api.nvim_buf_get_lines(buf, 0, -1, false),
+        "\n"
+    ) .. "\n"
+    local new_str = table.concat(new_lines, "\n") .. "\n"
+    local hunks = vim.text.diff(old_str, new_str, {
+        result_type = "indices",
+        algorithm = "histogram",
+    })
+    ---@cast hunks [integer, integer, integer, integer][]
+    if #hunks == 0 then
+        return
+    end
     vim.bo[buf].modifiable = true
-    vim.api.nvim_buf_set_lines(buf, 0, -1, false, util.split_lines(stdout))
+    for i = #hunks, 1, -1 do
+        local sa, ca, sb, cb = unpack(hunks[i])
+        local start = ca == 0 and sa or sa - 1
+        vim.api.nvim_buf_set_lines(
+            buf,
+            start,
+            start + ca,
+            false,
+            vim.list_slice(new_lines, sb, sb + cb - 1)
+        )
+    end
     vim.bo[buf].modifiable = false
     vim.bo[buf].modified = false
 end