Module INFO, support default section for simple modules

src/module.c

@@ -4709,9 +4709,12 @@ int RM_InfoEndDictField(RedisModuleInfoCtx *ctx);
 
 /* Used to start a new section, before adding any fields. the section name will
  * be prefixed by "<modulename>_" and must only include A-Z,a-z,0-9.
+ * NULL or empty string indicates the default section (only <modulename>) is used.
  * When return value is REDISMODULE_ERR, the section should and will be skipped. */
 int RM_InfoAddSection(RedisModuleInfoCtx *ctx, char *name) {
-    sds full_name = sdscatprintf(sdsdup(ctx->module->name), "_%s", name);
+    sds full_name = sdsdup(ctx->module->name);
+    if (name != NULL && strlen(name) > 0)
+        full_name = sdscatprintf(full_name, "_%s", name);
 
     /* Implicitly end dicts, instead of returning an error which is likely un checked. */
     if (ctx->in_dict_field)

tests/modules/infotest.c

@@ -3,6 +3,9 @@
 #include <string.h>
 
 void InfoFunc(RedisModuleInfoCtx *ctx, int for_crash_report) {
+    RedisModule_InfoAddSection(ctx, "");
+    RedisModule_InfoAddFieldLongLong(ctx, "global", -2);
+
     RedisModule_InfoAddSection(ctx, "Spanish");
     RedisModule_InfoAddFieldCString(ctx, "uno", "one");
     RedisModule_InfoAddFieldLongLong(ctx, "dos", 2);

tests/unit/moduleapi/infotest.tcl

@@ -14,12 +14,14 @@ start_server {tags {"modules"}} {
         set info [r info all]
         # info all does not contain modules
         assert { ![string match "*Spanish*" $info] }
+        assert { ![string match "*infotest*" $info] }
         assert { [string match "*used_memory*" $info] }
     }
 
     test {module info everything} {
         set info [r info everything]
         # info everything contains all default sections, but not ones for crash report
+        assert { [string match "*infotest_global*" $info] }
         assert { [string match "*Spanish*" $info] }
         assert { [string match "*Italian*" $info] }
         assert { [string match "*used_memory*" $info] }
@@ -31,6 +33,7 @@ start_server {tags {"modules"}} {
         set info [r info modules]
         # info all does not contain modules
         assert { [string match "*Spanish*" $info] }
+        assert { [string match "*infotest_global*" $info] }
         assert { ![string match "*used_memory*" $info] }
     }
 
@@ -39,12 +42,14 @@ start_server {tags {"modules"}} {
         # info all does not contain modules
         assert { [string match "*Spanish*" $info] }
         assert { ![string match "*used_memory*" $info] }
-    }
+        field $info infotest_global
+    } {-2}
 
     test {module info one section} {
         set info [r info INFOTEST_SPANISH]
         assert { ![string match "*used_memory*" $info] }
         assert { ![string match "*Italian*" $info] }
+        assert { ![string match "*infotest_global*" $info] }
         field $info infotest_uno
     } {one}