Prevent panic when send dests is nil

Signed-off-by: Yilun <[email protected]>
nknorg · Apr 29, 2020 · 6a43891 · 6a43891
1 parent 1af3944
commit 6a43891
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Showing 4 changed files with 21 additions and 13 deletions.
diff --git a/client.go b/client.go
@@ -735,7 +735,7 @@ func (c *Client) Send(dests *StringArray, data interface{}, config *MessageConfi
 		return nil, err
 	}
 
-	if err := c.send(dests.Elems, payload, !config.Unencrypted, config.MaxHoldingSeconds); err != nil {
+	if err := c.send(dests.Elems(), payload, !config.Unencrypted, config.MaxHoldingSeconds); err != nil {
 		return nil, err
 	}
 

diff --git a/config.go b/config.go
@@ -222,28 +222,28 @@ func GetDefaultTransactionConfig() *TransactionConfig {
 // GetRandomSeedRPCServerAddr returns a random seed rpc server address from the
 // client config.
 func (config *ClientConfig) GetRandomSeedRPCServerAddr() string {
-	if len(config.SeedRPCServerAddr.Elems) == 0 {
+	if config.SeedRPCServerAddr.Len() == 0 {
 		return ""
 	}
-	return config.SeedRPCServerAddr.Elems[rand.Intn(len(config.SeedRPCServerAddr.Elems))]
+	return config.SeedRPCServerAddr.Elems()[rand.Intn(config.SeedRPCServerAddr.Len())]
 }
 
 // GetRandomSeedRPCServerAddr returns a random seed rpc server address from the
 // wallet config.
 func (config *WalletConfig) GetRandomSeedRPCServerAddr() string {
-	if len(config.SeedRPCServerAddr.Elems) == 0 {
+	if config.SeedRPCServerAddr.Len() == 0 {
 		return ""
 	}
-	return config.SeedRPCServerAddr.Elems[rand.Intn(len(config.SeedRPCServerAddr.Elems))]
+	return config.SeedRPCServerAddr.Elems()[rand.Intn(config.SeedRPCServerAddr.Len())]
 }
 
 // GetRandomSeedRPCServerAddr returns a random seed rpc server address from the
 // rpc config.
 func (config *RPCConfig) GetRandomSeedRPCServerAddr() string {
-	if len(config.SeedRPCServerAddr.Elems) == 0 {
+	if config.SeedRPCServerAddr.Len() == 0 {
 		return ""
 	}
-	return config.SeedRPCServerAddr.Elems[rand.Intn(len(config.SeedRPCServerAddr.Elems))]
+	return config.SeedRPCServerAddr.Elems()[rand.Intn(config.SeedRPCServerAddr.Len())]
 }
 
 // MergeClientConfig merges a given client config with the default client config

diff --git a/multiclient.go b/multiclient.go
@@ -308,7 +308,7 @@ func (m *MultiClient) SendWithClient(clientID int, dests *StringArray, data inte
 		return nil, err
 	}
 
-	if err := m.sendWithClient(clientID, dests.Elems, payload, !config.Unencrypted, config.MaxHoldingSeconds); err != nil {
+	if err := m.sendWithClient(clientID, dests.Elems(), payload, !config.Unencrypted, config.MaxHoldingSeconds); err != nil {
 		return nil, err
 	}
 
@@ -374,7 +374,7 @@ func (m *MultiClient) Send(dests *StringArray, data interface{}, config *Message
 	go func() {
 		sent := 0
 		for clientID := range clients {
-			err := m.sendWithClient(clientID, dests.Elems, payload, !config.Unencrypted, config.MaxHoldingSeconds)
+			err := m.sendWithClient(clientID, dests.Elems(), payload, !config.Unencrypted, config.MaxHoldingSeconds)
 			if err == nil {
 				select {
 				case success <- struct{}{}:
@@ -557,7 +557,7 @@ func (m *MultiClient) Listen(addrsRe *StringArray) error {
 	if addrsRe == nil {
 		addrs = []string{DefaultSessionAllowAddr}
 	} else {
-		addrs = addrsRe.Elems
+		addrs = addrsRe.Elems()
 	}
 
 	var err error

diff --git a/util.go b/util.go
@@ -97,7 +97,7 @@ func (amount *Amount) ToFixed64() common.Fixed64 {
 
 // StringArray is a wrapper type for gomobile compatibility. StringArray is not
 // protected by lock and should not be read and write at the same time.
-type StringArray struct{ Elems []string }
+type StringArray struct{ elems []string }
 
 // NewStringArray creates a StringArray from a list of string elements.
 func NewStringArray(elems ...string) *StringArray {
@@ -110,14 +110,22 @@ func NewStringArrayFromString(s string) *StringArray {
 	return &StringArray{strings.Fields(s)}
 }
 
+// Elems returns the string array elements.
+func (sa *StringArray) Elems() []string {
+	if sa == nil {
+		return nil
+	}
+	return sa.elems
+}
+
 // Len returns the string array length.
 func (sa *StringArray) Len() int {
-	return len(sa.Elems)
+	return len(sa.Elems())
 }
 
 // Append adds an element to the string array.
 func (sa *StringArray) Append(s string) {
-	sa.Elems = append(sa.Elems, s)
+	sa.elems = append(sa.elems, s)
 }
 
 // StringMapFunc is a wrapper type for gomobile compatibility.