Fix RPC console parser to handle escaped arguments more like bash

- Fix issue #1750

src/qt/rpcconsole.cpp

@@ -13,7 +13,6 @@
 #include <QUrl>
 #include <QScrollBar>
 
-#include <boost/tokenizer.hpp>
 #include <openssl/crypto.h>
 
 // TODO: make it possible to filter out categories (esp debug messages when implemented)
@@ -54,34 +53,113 @@ void RPCExecutor::start()
    // Nothing to do
 }
 
+/**
+ * Split shell command line into a list of arguments. Aims to emulate \c bash and friends.
+ * 
+ * - Arguments are delimited with whitespace
+ * - Extra whitespace at the beginning and end and between arguments will be ignored
+ * - Arguments can be "double" or 'single' quoted. Those are treated the same.
+ * - The backslash '\' is used as escape character
+ *   - Outside quotes, any character can be escaped
+ *   - Within double quotes, only escape double quotes with \" and backslashes with \\
+ *   - Within single quotes, only escape single quotes with \' and backslashes with \\
+ *
+ * @param[out]   args        Parsed arguments will be appended to this list
+ * @param[in]    strCommand  Command line to split
+ */
+bool parseCommandLine(std::vector<std::string> &args, const std::string &strCommand)
+{
+    enum CmdParseState
+    {
+        STATE_EATING_SPACES,
+        STATE_ARGUMENT,
+        STATE_SINGLEQUOTED,
+        STATE_DOUBLEQUOTED,
+        STATE_ESCAPE_OUTER,
+        STATE_ESCAPE_SINGLEQUOTED,
+        STATE_ESCAPE_DOUBLEQUOTED
+    } state = STATE_EATING_SPACES;
+    std::string curarg;
+    foreach(char ch, strCommand)
+    {
+        switch(state)
+        {
+        case STATE_ARGUMENT: // After argument
+        case STATE_EATING_SPACES: // Handle runs of spaces
+            switch(ch)
+            {
+            case '"': state = STATE_DOUBLEQUOTED; break;
+            case '\'': state = STATE_SINGLEQUOTED; break;
+            case '\\': state = STATE_ESCAPE_OUTER; break;
+            case ' ': case '\n': case '\t':
+                if(state == STATE_ARGUMENT) // Space ends argument
+                {
+                    args.push_back(curarg);
+                    curarg.clear();
+                }
+                state = STATE_EATING_SPACES;
+                break;
+            default: curarg += ch; state = STATE_ARGUMENT;
+            }
+            break;
+        case STATE_SINGLEQUOTED: // Single-quoted string
+            switch(ch)
+            {
+            case '\'': state = STATE_ARGUMENT; break;
+            case '\\': state = STATE_ESCAPE_SINGLEQUOTED; break;
+            default: curarg += ch;
+            }
+            break;
+        case STATE_DOUBLEQUOTED: // Double-quoted string
+            switch(ch)
+            {
+            case '"': state = STATE_ARGUMENT; break;
+            case '\\': state = STATE_ESCAPE_DOUBLEQUOTED; break;
+            default: curarg += ch;
+            }
+            break;
+        case STATE_ESCAPE_OUTER: // '\' outside quotes
+            curarg += ch; state = STATE_ARGUMENT;
+            break;
+        case STATE_ESCAPE_SINGLEQUOTED: // '\' in single-quoted text
+            if(ch != '\'') curarg += '\\'; // keep '\' for everything but the quote
+            curarg += ch; state = STATE_SINGLEQUOTED;
+            break;
+        case STATE_ESCAPE_DOUBLEQUOTED: // '\' in double-quoted text
+            if(ch != '"') curarg += '\\'; // keep '\' for everything but the quote
+            curarg += ch; state = STATE_DOUBLEQUOTED;
+            break;
+        }
+    }
+    switch(state) // final state
+    {
+    case STATE_EATING_SPACES:
+        return true;
+    case STATE_ARGUMENT:
+        args.push_back(curarg);
+        return true;
+    default: // ERROR to end in one of the other states
+        return false;
+    }
+}
+
 void RPCExecutor::request(const QString &command)
 {
-    // Parse shell-like command line into separate arguments
+    std::vector<std::string> args;
-    std::string strMethod;
+    if(!parseCommandLine(args, command.toStdString()))
-    std::vector<std::string> strParams;
-    try {
-        boost::escaped_list_separator<char> els('\\',' ','\"');
-        std::string strCommand = command.toStdString();
-        boost::tokenizer<boost::escaped_list_separator<char> > tok(strCommand, els);
-
-        int n = 0;
-        for(boost::tokenizer<boost::escaped_list_separator<char> >::iterator beg=tok.begin(); beg!=tok.end();++beg,++n)
     {
-            if(n == 0) // First parameter is the command
+        emit reply(RPCConsole::CMD_ERROR, QString("Parse error: unbalanced ' or \""));
-                strMethod = *beg;
-            else
-                strParams.push_back(*beg);
-        }
-    }
-    catch(boost::escaped_list_error &e)
-    {
-        emit reply(RPCConsole::CMD_ERROR, QString("Parse error"));
         return;
     }
-
+    if(args.empty())
+        return; // Nothing to do
     try {
         std::string strPrint;
-        json_spirit::Value result = tableRPC.execute(strMethod, RPCConvertValues(strMethod, strParams));
+        // Convert argument list to JSON objects in method-dependent way,
+        // and pass it along with the method name to the dispatcher.
+        json_spirit::Value result = tableRPC.execute(
+            args[0],
+            RPCConvertValues(args[0], std::vector<std::string>(args.begin() + 1, args.end())));
 
         // Format result reply
         if (result.type() == json_spirit::null_type)