Clarify help messages for path args to mention datadir prefix

Change `-conf`'s and others' help messages to indicate that relative path
values will be prefixed by the datadir path. This behavior is confusing when
attempting to specify a configuration file in the current directory with
`-conf=bitcoin.conf`, but loading the `bitcoin.conf` file in ~/.bitcoin
datadir.

(cherry picked from commit bitcoin/bitcoin@a1e13055c2)

src/bitcoin-cli.cpp

@@ -39,7 +39,7 @@ std::string HelpMessageCli()
     std::string strUsage;
     strUsage += HelpMessageGroup(_("Options:"));
     strUsage += HelpMessageOpt("-?", _("This help message"));
-    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file (default: %s)"), BITCOIN_CONF_FILENAME));
+    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file. Relative paths will be prefixed by datadir location. (default: %s)"), BITCOIN_CONF_FILENAME));
     strUsage += HelpMessageOpt("-datadir=<dir>", _("Specify data directory (this path cannot use '~')"));
     strUsage += HelpMessageOpt("-stdin", _("Read extra arguments from standard input, one per line until EOF/Ctrl-D (recommended for sensitive information such as passphrases). If first extra argument is `walletpassphrase` then the first line(password) will not be echoed."));
     AppendParamsHelpMessages(strUsage);

src/init.cpp

@@ -343,7 +343,7 @@ std::string HelpMessage(HelpMessageMode mode)
         strUsage += HelpMessageOpt("-blocksonly", strprintf(_("Whether to reject transactions from network peers. Automatic broadcast and rebroadcast of any transactions from inbound peers is disabled, unless '-whitelistforcerelay' is '1', in which case whitelisted peers' transactions will be relayed. RPC transactions are not affected. (default: %u)"), DEFAULT_BLOCKSONLY));
     strUsage += HelpMessageOpt("-checkblocks=<n>", strprintf(_("How many blocks to check at startup (default: %u, 0 = all)"), DEFAULT_CHECKBLOCKS));
     strUsage += HelpMessageOpt("-checklevel=<n>", strprintf(_("How thorough the block verification of -checkblocks is (0-4, default: %u)"), DEFAULT_CHECKLEVEL));
-    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file (default: %s)"), BITCOIN_CONF_FILENAME));
+    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file. Relative paths will be prefixed by datadir location. (default: %s)"), BITCOIN_CONF_FILENAME));
     if (mode == HMM_BITCOIND)
     {
 #ifndef WIN32
@@ -353,7 +353,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-datadir=<dir>", _("Specify data directory (this path cannot use '~')"));
     strUsage += HelpMessageOpt("-paramsdir=<dir>", _("Specify Zcash network parameters directory"));
     strUsage += HelpMessageOpt("-dbcache=<n>", strprintf(_("Set database cache size in megabytes (%d to %d, default: %d)"), nMinDbCache, nMaxDbCache, nDefaultDbCache));
-    strUsage += HelpMessageOpt("-debuglogfile=<file>", strprintf(_("Specify location of debug log file: this can be an absolute path or a path relative to the data directory (default: %s)"), DEFAULT_DEBUGLOGFILE));
+    strUsage += HelpMessageOpt("-debuglogfile=<file>", strprintf(_("Specify location of debug log file. Relative paths will be prefixed by a net-specific datadir location. (default: %s)"), DEFAULT_DEBUGLOGFILE));
     strUsage += HelpMessageOpt("-exportdir=<dir>", _("Specify directory to be used when exporting data"));
     strUsage += HelpMessageOpt("-ibdskiptxverification", strprintf(_("Skip transaction verification during initial block download up to the last checkpoint height. Incompatible with flags that disable checkpoints. (default = %u)"), DEFAULT_IBD_SKIP_TX_VERIFICATION));
     strUsage += HelpMessageOpt("-loadblock=<file>", _("Imports blocks from external blk000??.dat file on startup"));
@@ -361,7 +361,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-par=<n>", strprintf(_("Set the number of script verification threads (%u to %d, 0 = auto, <0 = leave that many cores free, default: %d)"),
         -GetNumCores(), MAX_SCRIPTCHECK_THREADS, DEFAULT_SCRIPTCHECK_THREADS));
 #ifndef WIN32
-    strUsage += HelpMessageOpt("-pid=<file>", strprintf(_("Specify pid file (default: %s)"), BITCOIN_PID_FILENAME));
+    strUsage += HelpMessageOpt("-pid=<file>", strprintf(_("Specify pid file. Relative paths will be prefixed by a net-specific datadir location. (default: %s)"), BITCOIN_PID_FILENAME));
 #endif
     strUsage += HelpMessageOpt("-prune=<n>", strprintf(_("Reduce storage requirements by pruning (deleting) old blocks. This mode disables wallet support and is incompatible with -txindex. "
             "Warning: Reverting this setting requires re-downloading the entire blockchain. "
@@ -525,7 +525,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-server", _("Accept command line and JSON-RPC commands"));
     strUsage += HelpMessageOpt("-rest", strprintf(_("Accept public REST requests (default: %u)"), DEFAULT_REST_ENABLE));
     strUsage += HelpMessageOpt("-rpcbind=<addr>", _("Bind to given address to listen for JSON-RPC connections. Use [host]:port notation for IPv6. This option can be specified multiple times (default: bind to all interfaces)"));
-    strUsage += HelpMessageOpt("-rpccookiefile=<loc>", _("Location of the auth cookie (default: data dir)"));
+    strUsage += HelpMessageOpt("-rpccookiefile=<loc>", _("Location of the auth cookie. Relative paths will be prefixed by a net-specific datadir location. (default: data dir)"));
     strUsage += HelpMessageOpt("-rpcuser=<user>", _("Username for JSON-RPC connections"));
     strUsage += HelpMessageOpt("-rpcpassword=<pw>", _("Password for JSON-RPC connections"));
     strUsage += HelpMessageOpt("-rpcauth=<userpw>", _("Username and hashed password for JSON-RPC connections. The field <userpw> comes in the format: <USERNAME>:<SALT>$<HASH>. A canonical python script is included in share/rpcuser. This option can be specified multiple times"));