Glibc recently update from Unicode 5.1 to Unicode 7.0. This presentation explains all the details behind it with references.

1. Glibc Unicode and CLDRGlibc Unicode and CLDR
Pravin SatputePravin Satpute
Senior Software EngineerSenior Software Engineer
Globalization TeamGlobalization Team
Red HatRed Hat

2. AgendaAgenda
●
What was the problem?What was the problem?
●
Why so?Why so?
●
How we resolved issue?How we resolved issue?
● Analysis
● Development
●
Getting patch into upstreamGetting patch into upstream
●
Question and AnswersQuestion and Answers

3. What was the problem?What was the problem?

4. What was the problem?What was the problem?
● Updating Glibc localedata from Unicode 5.1 to
Unicode 7.0
● /usr/share/i18n/locales/i18n (LC_CTYPE)
● /usr/share/i18n/charmaps/UTF-8.gz

5. Why So?Why So?

6. What were the issues?What were the issues?
● No Documentation.
● Risk of missing backward compatibility.
● No expert.

7. How we resolved it?How we resolved it?

8. How we resolved it?How we resolved it?
AnalysisAnalysis
● Started gathering Changelog, Git logs for all changes
happened over the time. Specific fixes.
● Found hints, information written in Localedata files.
● Comments on Bugzilla
● Unicode source files providing raw information for Glibc
Localedata
● UnicodeData.txt
● DerivedCoreProperties.txt
● EastAsianWidth.txt

9. How we resolved it?How we resolved it?
Started with LC_CTYPE (i18n)Started with LC_CTYPE (i18n)
● Wrote script gen-unicode-ctype.py to update output
generated from gen-unicode-ctype.c
● Backward Compatiblity
● This script was comparing existing data with newly
generated and generating easy to understand report.
● Later Mike modify gen-unicode-ctype.py to deprecate
gen-unicode-ctype.c
● Repeated same process for UTF-8 charmap and WIDTH.

10. Patch prepared whatPatch prepared what
next?next?

11. Patch prepared what next?Patch prepared what next?
● Later Mike Fabian stepped into it.
● He reviewed scripts. Improved it.
● Glibc upstream further improved it.
● We proposed System wide change for Fedora 22

12. Patch prepared what next?Patch prepared what next?
● Patch got committed in upstream Feb last week.
● Collaborative work from Me, Mike Fabian,
Alexandre Oliva supported by Carlos and Jens
Petersen
● Users will get this update through Fedora 22 and
other upstream distros latest releases.

13. Questions??Questions??

14. ReferencesReferences
● https://github.com/pravins/glibc-i18n
● https://sourceware.org/bugzilla/show_bug.cgi?id=14094
● https://fedoraproject.org/wiki/Changes/Glibc_Unicode_7
● https://sourceware.org/git/?p=glibc.git;a=commit;h=4a4839c94a4c
93ffc0d5b95c69a08b02a57007f2