util/gconv: compatibility for bool pointer

[qinyuguang]

What do you want to ask?

Code

trueValue := true
falseValue := false
type T struct {
    True     bool  `json:"true"`
    False    bool  `json:"false"`
    TruePtr  *bool `json:"true_ptr"`
    FalsePtr *bool `json:"false_ptr"`
}
m := g.Map{
    "true":      trueValue,
    "false":     falseValue,
    "true_ptr":  &trueValue,
    "false_ptr": &falseValue,
}
t := &T{}
_ = gconv.Struct(m, &t)
gutil.DumpWithType(m, t)

v2.7.2 output

map[string]interface {}(4) {                                                                                                                                                                        
    string("false_ptr"): bool(false),                                                                                                                                                               
    string("true"):      bool(true),                                                                                                                                                                
    string("false"):     bool(false),                                                                                                                                                               
    string("true_ptr"):  bool(true),                                                                                                                                                                
}                                                                                                                                                                                                   
*main.T(4) {                                                                                                                                                                                        
    True:     bool(true),                                                                                                                                                                           
    False:    bool(false),                                                                                                                                                                          
    TruePtr:  bool(true),                                                                                                                                                                           
    FalsePtr: bool(false),                                                                                                                                                                          
} 

v2.7.3 output

map[string]interface {}(4) {                                                                                                                                                                        
    string("false_ptr"): bool(false),                                                                                                                                                               
    string("true"):      bool(true),                                                                                                                                                                
    string("false"):     bool(false),                                                                                                                                                               
    string("true_ptr"):  bool(true),                                                                                                                                                                
}                                                                                                                                                                                                   
*main.T(4) {                                                                                                                                                                                        
    True:     bool(true),                                                                                                                                                                           
    False:    bool(false),                                                                                                                                                                          
    TruePtr:  bool(true),                                                                                                                                                                           
    FalsePtr: bool(true),                                                                                                                                                                           
} 

Question

Need maintain compatibility when upgrading minor versions?

[wln32]

@qinyuguang 老版本的代码在没有改造前，对于 bool 类型的转换是以下流程
对于 *bool 类型，判断了是否为指针，如果是直接返回，且是浅复制

新版本的改造代码直接走了gconv.Bool函数的逻辑，里面对于指针的处理是以下流程

注册bool转换函数的代码

gconv.Bool函数的实现----只要指针非nil，就全部为true，这个逻辑理论上是错误的，

可能会导致以下情况

var f = new(bool) // f = &false 实际

var v= gconv.Bool(f)
fmt.Println(v)
// output: true

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---

@qinyuguang Before the old version of the code was modified, the conversion process for bool type was as follows
For the *bool type, it is judged whether it is a pointer, if it is returned directly, and it is a shallow copy

The new version of the modified code directly uses the logic of the gconv.Bool function. The processing of pointers is as follows:

Code to register bool conversion function

The implementation of the gconv.Bool function - as long as the pointer is non-nil, all are true. This logic is theoretically wrong.

This may lead to the following situations

var f = new(bool) // f = &false actual

var v= gconv.Bool(f)
fmt.Println(v)
// output: true