[Mono-bugs] [Bug 35975][Nor] New - System.IO.FileStream doesn't obey FileMode specifier

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Changed by jonpryor@vt.edu.

http://bugzilla.ximian.com/show_bug.cgi?id=35975

--- shadow/35975	Thu Dec 19 17:52:33 2002
+++ shadow/35975.tmp.10629	Thu Dec 19 17:52:33 2002
@@ -0,0 +1,65 @@
+Bug#: 35975
+Product: Mono/Class Libraries
+Version: unspecified
+OS: other
+OS Details: 
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Normal
+Component: CORLIB
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: jonpryor@vt.edu               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: System.IO.FileStream doesn't obey FileMode specifier
+
+Please fill in this template when reporting a bug, unless you know what you
+are doing.
+Description of Problem:
+
+System.IO.FileStream doesn't obey the FileMode specifier passed to the
+constructor.  In particular, it doesn't append text properly.
+
+Consider the following sample code:
+
+        // appending to a file...
+        using System;
+        using System.IO;
+
+        class R {
+          public static void AppendText (string file, string message) {
+            byte[] b = new byte[message.Length+1];
+            for (int i = 0; i != message.Length; ++i)
+              b[i] = (byte) message[i];
+            b[message.Length] = (byte) '\n';
+
+            using (FileStream fs = new FileStream (file, FileMode.Append, 
+                   FileAccess.Write, FileShare.None)) {
+              fs.Write (b, 0, b.Length);
+            }
+          }
+
+          public static void Main () {
+            AppendText ("af.txt", "Hello, world!");
+            AppendText ("af.txt", "Hello, world! 2");
+            AppendText ("af.txt", "Hello, world! 3");
+            AppendText ("af.txt", "Hello, world! 4");
+          }
+        }
+
+When compiled and executed with mono/mcs, the contents of `af.txt' contain:
+        Hello, world! 4
+
+I would expect it to contain:
+        Hello, world!
+        Hello, world! 2
+        Hello, world! 3
+        Hello, world! 4
+i.e. actually append text to the file. ;-)
+
+The problem seems to be generated because the FileMode value is only used
+in the function call MonoIO.Open (line 89), but it isn't used to set the
+current position in the file (buf_offset) in InitBuffer() (line 448).