Add AbsPathForConfigVal to consolidate datadir prefixing for path args

Most commandline/config args are interpreted as relative to datadir if
not passed absolute. Consolidate the logic for this normalization.

src/rpc/protocol.cpp

@@ -72,9 +72,7 @@ static fs::path GetAuthCookieFile(bool temp=false)
     if (temp) {
         arg += ".tmp";
     }
-    fs::path path(arg);
-    if (!path.is_complete()) path = GetDataDir() / path;
-    return path;
+    return AbsPathForConfigVal(fs::path(arg));
 }
 
 bool GenerateAuthCookie(std::string *cookie_out)

src/util.cpp

@@ -4,6 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <util.h>
+#include <fs.h>
 
 #include <chainparamsbase.h>
 #include <random.h>
@@ -188,11 +189,7 @@ static void DebugPrintInit()
 fs::path GetDebugLogPath()
 {
     fs::path logfile(gArgs.GetArg("-debuglogfile", DEFAULT_DEBUGLOGFILE));
-    if (logfile.is_absolute()) {
-        return logfile;
-    } else {
-        return GetDataDir() / logfile;
-    }
+    return AbsPathForConfigVal(logfile);
 }
 
 bool OpenDebugLog()
@@ -624,11 +621,7 @@ void ClearDatadirCache()
 
 fs::path GetConfigFile(const std::string& confPath)
 {
-    fs::path pathConfigFile(confPath);
-    if (!pathConfigFile.is_complete())
-        pathConfigFile = GetDataDir(false) / pathConfigFile;
-
-    return pathConfigFile;
+    return AbsPathForConfigVal(fs::path(confPath), false);
 }
 
 void ArgsManager::ReadConfigFile(const std::string& confPath)
@@ -663,9 +656,7 @@ void ArgsManager::ReadConfigFile(const std::string& confPath)
 #ifndef WIN32
 fs::path GetPidFile()
 {
-    fs::path pathPidFile(gArgs.GetArg("-pid", BITCOIN_PID_FILENAME));
-    if (!pathPidFile.is_complete()) pathPidFile = GetDataDir() / pathPidFile;
-    return pathPidFile;
+    return AbsPathForConfigVal(fs::path(gArgs.GetArg("-pid", BITCOIN_PID_FILENAME)));
 }
 
 void CreatePidFile(const fs::path &path, pid_t pid)
@@ -936,3 +927,8 @@ int64_t GetStartupTime()
 {
     return nStartupTime;
 }
+
+fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific)
+{
+    return fs::absolute(path, GetDataDir(net_specific));
+}

src/util.h

@@ -191,6 +191,16 @@ bool OpenDebugLog();
 void ShrinkDebugFile();
 void runCommand(const std::string& strCommand);
 
+/**
+ * Most paths passed as configuration arguments are treated as relative to
+ * the datadir if they are not absolute.
+ *
+ * @param path The path to be conditionally prefixed with datadir.
+ * @param net_specific Forwarded to GetDataDir().
+ * @return The normalized path.
+ */
+fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific = true);
+
 inline bool IsSwitchChar(char c)
 {
 #ifdef WIN32