Fix RESP parser - Allow Redis return empty array (#45)

redis · Apr 21, 2024 · 581221f · 581221f
1 parent 6c54c27
commit 581221f
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Showing 2 changed files with 30 additions and 11 deletions.
diff --git a/src/ext/readerResp.c b/src/ext/readerResp.c
@@ -197,9 +197,10 @@ RespRes readRespReplyBulk(RespReaderCtx *ctx, RespReplyBuff *buffInfo) {
                     return RESP_REPLY_ERR;
                 }
 
+                /* If empty bulk */
                 if (ctx->bulkLen == 0) {
-                    snprintf(ctx->errorMsg, sizeof(ctx->errorMsg), "Response Bulk must be bigger than zero");
-                    return RESP_REPLY_ERR;
+                    ctx->typeState = PROC_BULK_READ_END;
+                    break;
                 }
 
                 ctx->typeState = PROC_BULK_READ;
@@ -232,11 +233,12 @@ RespRes readRespReplyBulk(RespReaderCtx *ctx, RespReplyBuff *buffInfo) {
                 }
 
                 ctx->typeState = PROC_BULK_READ_END;
-                /* fall-through */
+                break;
+        }
 
-            case PROC_BULK_READ_END:
-                ctx->typeState = 0;
-                return RESP_REPLY_OK;
+        if (ctx->typeState == PROC_BULK_READ_END) {
+            ctx->typeState = PROC_BULK_READ_INIT;
+            return RESP_REPLY_OK;
         }
     }
 }
@@ -299,9 +301,10 @@ static RespRes readRespReplyBulkArray(RespReaderCtx *ctx, RespReplyBuff *buffInf
                     return RESP_REPLY_ERR;
                 }
 
+                /* if empty array then jump to READ_END of array */
                 if (ctx->numBulksArray == 0) {
-                    snprintf(ctx->errorMsg, sizeof(ctx->errorMsg), "Bulk Array must be bigger than zero");
-                    return RESP_REPLY_ERR;
+                    ctx->typeArrayState = READ_END;
+                    break;
                 }
 
                 ctx->typeArrayState = READ_NEXT_BULK_HDR;
@@ -324,10 +327,12 @@ static RespRes readRespReplyBulkArray(RespReaderCtx *ctx, RespReplyBuff *buffInf
                     break;
                 }
                 ctx->typeArrayState = READ_END; /* fall-through */
+                break;
+        }
 
-            case READ_END:
-                ctx->typeArrayState = 0;
-                return RESP_REPLY_OK;
+        if (ctx->typeArrayState == READ_END) {
+            ctx->typeArrayState = READ_INIT;
+            return RESP_REPLY_OK;
         }
     }
 }

diff --git a/test/test_resp_reader.c b/test/test_resp_reader.c
@@ -27,6 +27,18 @@ static void test_single_status(void **state) {
                             1, RESP_REPLY_OK, 1);
 }
 
+static void test_empty_array(void **state) {
+    UNUSED(state);
+    test_resp_reader_common(NULL, STR_AND_SIZE("*0\r\n"),
+                            1, RESP_REPLY_OK, 1);
+}
+
+static void test_empty_bulk(void **state) {
+    UNUSED(state);
+    test_resp_reader_common(NULL, STR_AND_SIZE("$0\r\n"),
+                            1, RESP_REPLY_OK, 1);
+}
+
 static void test_single_int(void **state) {
     UNUSED(state);
     test_resp_reader_common(NULL, STR_AND_SIZE(":1\r\n"),
@@ -141,6 +153,8 @@ static void test_mixture_and_fragmented(void **state) {
 int group_test_resp_reader(void) {
     const struct CMUnitTest tests[] = {
             cmocka_unit_test(test_single_status),
+            cmocka_unit_test(test_empty_array),
+            cmocka_unit_test(test_empty_bulk),
             cmocka_unit_test(test_single_int),
             cmocka_unit_test(test_array_single_bulk),
             cmocka_unit_test(test_array_3_bulks),