Fix #244 Exception with RollingFileAppender when files are already present (#251)

gdziadkiewicz · web-flow · commit f163d30e4f4c · 2025-06-06T19:33:13.000+02:00
diff --git a/src/log4net/Appender/RollingFileAppender.cs b/src/log4net/Appender/RollingFileAppender.cs
@@ -791,7 +791,8 @@ private void InitializeFromOneFile(string baseFile, string curFileName)
   {
     curFileName = curFileName.ToLowerInvariant();
     baseFile = baseFile.ToLowerInvariant();
-    var baseFileWithoutExtension = Path.Combine(Path.GetDirectoryName(baseFile) ?? "", Path.GetFileNameWithoutExtension(baseFile));
+    string dir = string.IsNullOrEmpty(baseFile) ? "" : Path.GetDirectoryName(baseFile);
+    var baseFileWithoutExtension = Path.Combine(dir ?? "", Path.GetFileNameWithoutExtension(baseFile));
     
     if (curFileName.StartsWith(baseFileWithoutExtension) == false)
     {

Original file line number	Diff line number	Diff line change
`@@ -791,7 +791,8 @@ private void InitializeFromOneFile(string baseFile, string curFileName)`
`791`	`791`	`{`
`792`	`792`	`curFileName = curFileName.ToLowerInvariant();`
`793`	`793`	`baseFile = baseFile.ToLowerInvariant();`
`794`		`- var baseFileWithoutExtension = Path.Combine(Path.GetDirectoryName(baseFile) ?? "", Path.GetFileNameWithoutExtension(baseFile));`
	`794`	`+ string dir = string.IsNullOrEmpty(baseFile) ? "" : Path.GetDirectoryName(baseFile);`
	`795`	`+ var baseFileWithoutExtension = Path.Combine(dir ?? "", Path.GetFileNameWithoutExtension(baseFile));`
`795`	`796`
`796`	`797`	`if (curFileName.StartsWith(baseFileWithoutExtension) == false)`
`797`	`798`	`{`