Exception thrown when *Format methods are given a malformed format string

• Key: LOG4NET-69
• Type: Bug
• Status: Resolved
• Resolution: Fixed
• Priority: Critical
• Assignee: Nicko Cadell
• Reporter: Ron Grabowski
• Affects Version/s: 1.2.9
• Fix Version/s: 1.2.10

Description

FormatException thrown when *Format methods are given a malformed format string: log.DebugFormat("Malformed {{,,,5}format{8}!");

This statement:

 log.DebugFormat("Malformed {{,,,5}format{8}!");

throws the following exception:

[FormatException: Input string was not in a correct format.]
   System.Text.StringBuilder.FormatError()
   System.Text.StringBuilder.AppendFormat(IFormatProvider provider, String format, Object[] args)
   System.String.Format(IFormatProvider provider, String format, Object[] args)
   log4net.Core.LogImpl.DebugFormat(String format, Object[] args)

which is consistent with the documentation for String.Format:

System.FormatException: The format item in format is invalid. -or- The number indicating an argument to format is less than zero, or greater than or equal to the number of specified objects to format.

Comments

Reduced length of summary as it formats better in the release notes

[Nicko Cadell]

version 1.2.10 does not actualy exist yet so this issue does not affect it. The issue exists in the latest source code at present but should hopefully be fixed shortly.

[Nicko Cadell]

This is fixed and i have added a test to ensure that malformed format strings don't leak exceptions.