Source: fontforge
Version: 1:20230101~dfsg-8
Severity: wishlist
Tags: patch
User: [email protected]
Usertags: timezone toolchain
X-Debbugs-Cc: [email protected]
Hi,
Whilst working on the Reproducible Builds effort [0], we noticed that
fontforge generates .afm and .pfb files that are unreproducible.
Specifically, whilst they use SOURCE_DATE_EPOCH for the timestamps,
they still vary on the timezone due to the use of ctime(3).
Patch attached, which at least causes packages such as t1-teams to be
reproducible.
However, there are many other ctime callsites in the codebase that might
require upstream to investigate: some of them are for ~diagnostic output
for human consumption, so likely should specify the timezone explicitly,
whatever it is.
(Alternatively, another method could be added to gutils/gutils.c alongside
GetTime that will return asctime(gmtime(arg)) if SOURCE_DATE_EPOCH is present,
otherwise return cmtime(arg), and then callsites could use this one.)
[0] https://reproducible-builds.org/
Regards,
--
,''`.
: :' : Chris Lamb
`. `'` [email protected] / chris-lamb.co.uk
`-
diff --git fontforge/dumppfa.c fontforge/dumppfa.c
index 7acdedc..aad2c73 100644
--- fontforge/dumppfa.c
+++ fontforge/dumppfa.c
@@ -1780,7 +1780,7 @@ static void dumpfontcomments(void (*dumpchar)(int ch,void
*data), void *data,
dumpf(dumpchar,data,"%%%%Title: %s\n", sf->fontname);
dumpf(dumpchar,data,"%%Version: %s\n", sf->version);
}
- dumpf(dumpchar,data,"%%%%CreationDate: %s", ctime(&now));
+ dumpf(dumpchar,data,"%%%%CreationDate: %s", asctime(gmtime(&now)));
if ( author!=NULL )
dumpf(dumpchar,data,"%%%%Creator: %s\n", author);
diff --git fontforge/splinesaveafm.c fontforge/splinesaveafm.c
index 15b42b7..4c96eda 100644
--- fontforge/splinesaveafm.c
+++ fontforge/splinesaveafm.c
@@ -1184,7 +1184,7 @@ static void AfmSplineFontHeader(FILE *afm, SplineFont
*sf, int formattype,
"StartFontMetrics 2.0\n" );
fprintf( afm, "Comment Generated by FontForge %s\n", FONTFORGE_VERSION );
now = GetTime();
- fprintf(afm,"Comment Creation Date: %s", ctime(&now));
+ fprintf(afm,"Comment Creation Date: %s", asctime(gmtime(&now)));
fprintf( afm, "FontName %s\n", sf->fontname );
if ( sf->fullname!=NULL ) fprintf( afm, "FullName %s\n", sf->fullname );
if ( sf->familyname!=NULL ) fprintf( afm, "FamilyName %s\n",
sf->familyname );
