lib-settings: Avoid unnecessary string duplications

diff --git a/src/lib-settings/settings.c b/src/lib-settings/settings.c
index e65668f94322f175217329a72a19daff0ff279f2..6f074815a70aedc501ab6e394b168d2157c6489f 100644 (file)
--- a/src/lib-settings/settings.c
+++ b/src/lib-settings/settings.c
@@ -548,6 +548,7 @@ settings_var_expand(struct settings_apply_ctx *ctx, unsigned int key_idx,
                    const char **value, const char **error_r)
 {
        struct settings_file file;
+       const char *orig_value = *value;
 
        if ((ctx->flags & SETTINGS_GET_FLAG_NO_EXPAND) != 0)
                return 0;
@@ -570,11 +571,11 @@ settings_var_expand(struct settings_apply_ctx *ctx, unsigned int key_idx,
                /* unchanged value */
                if (ctx->info->defines[key_idx].type == SET_FILE) {
                        /* Restore full SET_FILE value */
-                       *value = settings_file_get_value(&ctx->mpool->pool, &file);
+                       *value = orig_value;
                }
                return 0;
        } else if (ctx->info->defines[key_idx].type == SET_FILE) {
-               file.path = p_strdup(&ctx->mpool->pool, str_c(ctx->str));
+               file.path = str_c(ctx->str);
                *value = settings_file_get_value(&ctx->mpool->pool, &file);
                return 1;
        } else {
@@ -1859,6 +1860,7 @@ settings_instance_override(struct settings_apply_ctx *ctx,
                        /* setting doesn't exist in this info */
                        continue;
                }
+               bool value_needs_dup = (value != set->value);
                bool track_seen = TRUE;
                if (ctx->info->defines[key_idx].type == SET_FILTER_ARRAY) {
                        track_seen = FALSE;
@@ -1917,13 +1919,17 @@ settings_instance_override(struct settings_apply_ctx *ctx,
                           config process, but we get here with -O parameter
                           or with SETTINGS_OVERRIDE_TYPE_2ND_DEFAULT. */
                        const char *error;
-                       if (settings_var_expand(ctx, key_idx, &value,
-                                               &error) < 0) {
+                       ret = settings_var_expand(ctx, key_idx, &value, &error);
+                       if (ret < 0) {
                                *error_r = t_strdup_printf(
                                        "Failed to expand default setting %s=%s variables: %s",
                                        key, value, error);
                                return -1;
                        }
+                       if (ret > 0) {
+                               /* value was already strdup()ed */
+                               value_needs_dup = FALSE;
+                       }
                }
                if (ctx->info->defines[key_idx].type == SET_FILTER_ARRAY &&
                    set->type <= SETTINGS_OVERRIDE_TYPE_CLI_PARAM &&
@@ -1934,9 +1940,9 @@ settings_instance_override(struct settings_apply_ctx *ctx,
                        return -1;
                }
 
-               if (value != set->value)
+               if (value_needs_dup)
                        value = p_strdup(&ctx->mpool->pool, value);
-               else {
+               else if (value == set->value) {
                        /* Add explicit reference to instance->pool, which is
                           kept by the settings struct's pool. This allows
                           settings to survive even if the instance is freed.