lib-settings: Pad initial var expand context with empty tables and providers when...

Fixes:
Panic: file settings.c: line 1560 (settings_var_expand_init_add): assertion failed: (I_MAX(num_tables, num_provs) == num_ctx)

diff --git a/src/lib-settings/settings.c b/src/lib-settings/settings.c
index ec60f7ad0864973e80ef57af179c63da56c3c717..8e4ac6aef94780a32de7350de81d98961b911bea 100644 (file)
--- a/src/lib-settings/settings.c
+++ b/src/lib-settings/settings.c
@@ -1407,33 +1407,67 @@ settings_var_expand_init_add(struct settings_var_expand_init_ctx *init_ctx,
                             const struct var_expand_params *params)
 {
        unsigned int need_contexts = 1;
+       static const struct var_expand_table empty_table[] = {
+               VAR_EXPAND_TABLE_END
+       };
+       static const struct var_expand_table *empty_table_ptr = empty_table;
+       static const struct var_expand_provider empty_provider[] = {
+               VAR_EXPAND_TABLE_END
+       };
+       static const struct var_expand_provider *empty_provider_ptr = empty_provider;
+
        if (params->table != NULL) {
                i_assert(params->tables_arr == NULL);
                array_push_back(&init_ctx->tables, &params->table);
+       } else if (params->tables_arr == NULL && params->providers_arr == NULL) {
+               array_push_back(&init_ctx->tables, &empty_table_ptr);
        }
        if (params->providers != NULL) {
                i_assert(params->providers_arr == NULL);
                array_push_back(&init_ctx->providers, &params->providers);
+       } else if (params->tables_arr == NULL && params->providers_arr == NULL) {
+               array_push_back(&init_ctx->providers, &empty_provider_ptr);
        }
        if (params->table != NULL || params->providers != NULL)
                array_push_back(&init_ctx->contexts, &params->context);
 
-       if (params->tables_arr != NULL) {
-               for (unsigned int i = 0; params->tables_arr[i] != NULL; i++) {
-                       if (i > need_contexts)
-                               need_contexts = i;
-                       array_push_back(&init_ctx->tables,
-                                       &params->tables_arr[i]);
-               }
-       }
-       if (params->providers_arr != NULL) {
-               for (unsigned int i = 0; params->providers_arr[i] != NULL; i++) {
-                       if (i > need_contexts)
-                               need_contexts = i;
-                       array_push_back(&init_ctx->providers,
-                                       &params->providers_arr[i]);
-               }
+       if (params->tables_arr != NULL || params->providers_arr != NULL) {
+               unsigned int table_count = 0, prov_count = 0;
+               const struct var_expand_table *tbl;
+               const struct var_expand_provider *prov;
+
+               /* Ensure that we get a table and provider so that contexts line up */
+               do {
+                       tbl = params->tables_arr != NULL ?
+                               params->tables_arr[table_count] : NULL;
+                       prov = params->providers_arr != NULL ?
+                               params->providers_arr[prov_count] : NULL;
+
+                       /* for each provider and table, there needs to be
+                          a correspoding entry in both arrays to make sure
+                          that when we go through them, we get the correct
+                          context too.
+                       */
+                       if (tbl != NULL) {
+                               array_push_back(&init_ctx->tables, &tbl);
+                               table_count++;
+                       } else if (prov != NULL) {
+                               array_push_back(&init_ctx->tables, &empty_table_ptr);
+                       }
+                       if (prov != NULL) {
+                               array_push_back(&init_ctx->providers, &prov);
+                               prov_count++;
+                       } else if (tbl != NULL) {
+                               array_push_back(&init_ctx->providers, &empty_provider_ptr);
+                       }
+                       if (prov == NULL && tbl == NULL)
+                               break;
+               } while (tbl != NULL || prov != NULL);
+
+               if (I_MAX(table_count, prov_count) > need_contexts)
+                       need_contexts = I_MAX(table_count, prov_count);
        }
+
        if (params->escape_func != NULL)
                init_ctx->escape_func = params->escape_func;
        if (params->escape_context != NULL)
@@ -1447,6 +1481,11 @@ settings_var_expand_init_add(struct settings_var_expand_init_ctx *init_ctx,
                        array_push_back(&init_ctx->contexts, ctx);
                }
                i_assert(count == need_contexts);
+       } else {
+               /* Make sure we push some context enough to pad the context stack
+                  to match the number of tables and providers. */
+               for (unsigned int i = 1; i < need_contexts; i++)
+                       array_push_back(&init_ctx->contexts, &params->context);
        }
 
        /* ensure everything is still good */