Save a few string allocations when importing environment variables

1 files changed, 3 insertions, 2 deletions

diff --git a/src/env.cpp b/src/env.cpp
index 28ea51b0..c24280bc 100644
--- a/src/env.cpp
+++ b/src/env.cpp
@@ -450,6 +450,7 @@ void env_init(const struct config_paths_t *paths /* or NULL */)
     */
 
     /* Import environment variables. Walk backwards so that the first one out of any duplicates wins (#2784) */
+    wcstring key, val;
     const char * const * envp = (environ ? environ : __environ);
     size_t i = 0;
     while (envp && envp[i])
@@ -468,9 +469,9 @@ void env_init(const struct config_paths_t *paths /* or NULL */)
         }
         else
         {
-            wcstring key = key_and_val.substr(0, eql);
+            key.assign(key_and_val, 0, eql);
             if (is_read_only(key) || is_electric(key)) continue;
-            wcstring val = key_and_val.substr(eql + 1);
+            val.assign(key_and_val, eql + 1, wcstring::npos);
             if (variable_is_colon_delimited_array(key))
             {
                 std::replace(val.begin(), val.end(), L':', ARRAY_SEP);