mysql : 修复读写负数导致溢出处错误 (#1182) (#1183)

* mysql : 修复读写负数导致溢出处错误 #1182

* modify mysql test cases

* 对于db内部整型值的处理使用独立函数

lualib/skynet/db/mysql.lua

@@ -4,6 +4,8 @@
 -- The license is under the BSD license.
 -- Modified by Cloud Wu (remove bit32 for lua 5.3)
 
+-- protocol detail: https://mariadb.com/kb/en/clientserver-protocol/
+
 local socketchannel = require "skynet.socketchannel"
 local crypt = require "skynet.crypt"
 
@@ -100,7 +102,10 @@ local function _get_byte1(data, i)
     return strbyte(data, i), i + 1
 end
 
-local function _get_int1(data, i)
+local function _get_int1(data, i, is_signed)
+    if not is_signed then
+        return strunpack("<I1", data, i)
+    end
     return strunpack("<i1", data, i)
 end
 
@@ -108,7 +113,10 @@ local function _get_byte2(data, i)
     return strunpack("<I2", data, i)
 end
 
-local function _get_int2(data, i)
+local function _get_int2(data, i, is_signed)
+    if not is_signed then
+        return strunpack("<I2", data, i)
+    end
     return strunpack("<i2", data, i)
 end
 
@@ -116,11 +124,21 @@ local function _get_byte3(data, i)
     return strunpack("<I3", data, i)
 end
 
+local function _get_int3(data, i, is_signed)
+    if not is_signed then
+        return strunpack("<I3", data, i)
+    end
+    return strunpack("<i3", data, i)
+end
+
 local function _get_byte4(data, i)
     return strunpack("<I4", data, i)
 end
 
-local function _get_int4(data, i)
+local function _get_int4(data, i, is_signed)
+    if not is_signed then
+        return strunpack("<I4", data, i)
+    end
     return strunpack("<i4", data, i)
 end
 
@@ -128,7 +146,10 @@ local function _get_byte8(data, i)
     return strunpack("<I8", data, i)
 end
 
-local function _get_int8(data, i)
+local function _get_int8(data, i, is_signed)
+    if not is_signed then
+        return strunpack("<I8", data, i)
+    end
     return strunpack("<i8", data, i)
 end
 
@@ -354,10 +375,13 @@ local function _parse_field_packet(data)
     charsetnr, pos = _get_byte2(data, pos)
     length, pos = _get_byte4(data, pos)
     col.type = strbyte(data, pos)
+    pos = pos + 1
+    local flags, pos = _get_byte2(data, pos)
+    if flags & 0x20 == 0 then -- https://mariadb.com/kb/en/resultset/
+        col.is_signed = true
+    end
 
     --[[
-    pos = pos + 1
-    col.flags, pos = _get_byte2(data, pos)
     col.decimals = strbyte(data, pos)
     pos = pos + 1
     local default = sub(data, pos + 2)
@@ -812,6 +836,7 @@ local _binary_parser = {
     [0x05] = _get_double,
     [0x07] = _get_datetime,
     [0x08] = _get_int8,
+    [0x09] = _get_int3,
     [0x0c] = _get_datetime,
     [0x0f] = _from_length_coded_str,
     [0x10] = _from_length_coded_str,
@@ -859,7 +884,7 @@ local function _parse_row_data_binary(data, cols, compact)
             if not parser then
                 error("_parse_row_data_binary()error,unsupported field type " .. typ)
             end
-            value, pos = parser(data, pos)
+            value, pos = parser(data, pos, col.is_signed)
             if compact then
                 row[i] = value
             else

test/testmysql.lua

@@ -117,6 +117,21 @@ local function test_sp_blob(db)
 	print("test stored procedure ok")
 end
 
+local function test_signed(db)
+    local res = db:query("drop table if exists test_i_u")
+    res = db:query("create table test_i_u (i tinyint primary key, u tinyint unsigned)")
+    print(dump(res))
+
+    res = db:query("insert into test_i_u (i,u) values (-1,1),(127,128),(-127,255)")
+    print(dump(res))
+
+    local prep = "SELECT * FROM test_i_u"
+    local stmt = db:prepare(prep)
+    local res = db:execute(stmt)
+    print("test_i_u: ", dump(res))
+    db:stmt_close(stmt)
+end
+
 skynet.start(function()
 
 	local function on_connect(db)
@@ -151,6 +166,8 @@ skynet.start(function()
 
 	-- 测试存储过程和二进制blob
 	test_sp_blob(db)
+	
+	test_signed(db)
 
     -- test in another coroutine
 	skynet.fork( test2, db)