pluginName is empty lead to panic

[fifsky]

mysql/packets.go

Line 235 in 64db0f7

pluginName = string(data[pos:])

Before I always use the library link AnalyticDB of Ali cloud, it is compatible with the MySQL protocol, but I recently updated the MySQL driver, after I get error message "unknown authentication plugin name ' '", after screening, found the following information, I did some adjustment to apply my application, hope these information can have some help

I printer data variable:

======>data: [10 53 46 49 46 51 49 45 109 121 115 113 108 45 97 100 115 0 118 37 242 9 89 116 86 49 69 90 77 112 97 104 48 81 54 84 79 54 51 86 67 112 0 0 0 0 0 0 0 97 104 48 81 54 84 79 54 51 86 67 112 0]
======>data: 
5.1.31-mysql-adsv%�     YtV1EZMpah0Q6TO63VCpah0Q6TO63VCp

I made the following changes to accommodate my code,Line[232:236]

before

		if end := bytes.IndexByte(data[pos:], 0x00); end != -1 {
			pluginName = string(data[pos : pos+end])
		} else {
			pluginName = data[pos:]
		}

after

		if end := bytes.IndexByte(data[pos:], 0x00); end != -1 {
			pluginName = string(data[pos : pos+end])
		} else {
			if p := string(data[pos:]); p != "" {
				pluginName = p
			}
		}

[julienschmidt]

duplicate of #806