use explicit string comparison

Author: kotl

contrib/src/modem/db/get-command.cpp

@@ -16,7 +16,7 @@ bool GetCommand::execute(const String& command,
   String path = in->readLine();
   String value = fbase().getString(path);
 
-  if (fbase().error()) {
+  if (fbase().error() != "") {
     out->print("-FAIL ");
     out->println(fbase().error().c_str());
     return false;

contrib/src/modem/db/push-command.cpp

@@ -19,7 +19,7 @@ bool PushCommand::execute(const String& command,
 
   fbase().pushString(path, data);
 
-  if (fbase().error()) {
+  if (fbase().error() != "") {
     out->print("-FAIL ");
     out->println(fbase().error().c_str());
     return false;

contrib/src/modem/db/remove-command.cpp

@@ -16,7 +16,7 @@ bool RemoveCommand::execute(const String& command,
   String path = in->readLine();
   fbase().remove(path);
 
-  if (fbase().error()) {
+  if (fbase().error() != "") {
     out->print("-FAIL ");
     out->println(fbase().error().c_str());
     return false;

contrib/src/modem/db/set-command.cpp

@@ -19,7 +19,7 @@ bool SetCommand::execute(const String& command,
 
   fbase().setString(path, data);
 
-  if (fbase().error()) {
+  if (fbase().error() != "") {
     out->print("-FAIL ");
     out->println(fbase().error().c_str());
     return false;

contrib/src/modem/db/stream-command.cpp

@@ -13,10 +13,10 @@ bool StreamCommand::execute(const String& command,
     return false;
   }
 
-  std::string path = in->readLine().c_str();
+  String path = in->readLine().c_str();
   fbase().stream(path);  
 
-  if (fbase().error()) {
+  if (fbase().error() != "") {
     out->print("-FAIL ");
     out->println(fbase().error().c_str());
     return false;