[PATCH/RFC] dpkg: option to install package maintainer's configuration files

[Daniel Bock <daniel.bock@web.de>]

The option --overwrite-conffiles is added to dpkg. It allows to install 
the package maintainer's configuration files. If the file has been 
modified by the user, an backups is stored as .dpkg-old.

Signed-off-by: Daniel Bock <daniel.bock@web.de>
---

diff -upr ./a/man/dpkg.1 ./b/man/dpkg.1
--- ./a/man/dpkg.1    2010-04-15 13:38:57.000000000 +0200
+++ ./b/man/dpkg.1    2010-07-01 19:29:45.419722074 +0200
@@ -470,6 +470,10 @@ end up with undesirable results. (e.g. \
 \-\-no\-act\fP will first purge package foo and then try to purge package
 \-\-no\-act, even though you probably expected it to actually do nothing)
 .TP
+\fB\-\-overwrite-conffiles\fP
+Install the package maintainer's configuration files. If the file has been
+modified by the user, an backup is stored as \fB*.dpkg-old\fP.
+.TP
 \fB\-R\fP, \fB\-\-recursive\fP
 Recursively handle all regular files matching pattern \fB*.deb\fP
 found at specified directories and all of its subdirectories. This can
diff -upr ./a/src/configure.c ./b/src/configure.c
--- ./a/src/configure.c    2010-04-15 13:38:58.000000000 +0200
+++ ./b/src/configure.c    2010-07-01 19:30:15.607692547 +0200
@@ -145,6 +145,24 @@ deferred_configure_conffile(struct pkgin
         if (!strcmp(currenthash, NONEXISTENTFLAG))
             what |= cfof_userrmd;
     }
+
+    if (strcmp(currenthash, newdisthash) != 0 && f_overwriteconf) {
+        if (useredited) {
+            fprintf(stderr, "\n");
+
+            fprintf(stderr, !(what & cfof_userrmd) ?
+                        _("Configuration file '%s' has been modified.\n") :
+                        _("Configuration file '%s' has been deleted.\n"),
+                    usenode->name);
+
+            fprintf(stderr, _("Installing package maintainer's"
+                              " version of configuration file"
+                              " as you requested.\n"));
+            what &= cfof_userrmd;
+            what |= cfo_install | cfof_backup;
+        } else
+            what = cfo_newconff;
+    }

     debug(dbg_conff,
           "deferred_configure '%s' (= '%s') useredited=%d 
distedited=%d what=%o",
@@ -189,8 +207,9 @@ deferred_configure_conffile(struct pkgin
                         pkg->name, cdr.buf, cdr2.buf, strerror(errno));
         /* Fall through. */
     case cfo_install:
-        printf(_("Installing new version of config file %s ...\n"),
-               usenode->name);
+        if (!(f_overwriteconf && useredited))
+            printf(_("Installing new version of config file %s ...\n"),
+                   usenode->name);
     case cfo_newconff:
         strcpy(cdr2rest, DPKGNEWEXT);
         trig_file_activate(usenode, pkg);
diff -upr ./a/src/main.c ./b/src/main.c
--- ./a/src/main.c    2010-04-15 13:38:58.000000000 +0200
+++ ./b/src/main.c    2010-07-01 18:54:10.315710869 +0200
@@ -137,6 +137,7 @@ usage(const struct cmdinfo *ci, const ch
 "  --log=<filename>           Log status changes and actions to 
<filename>.\n"
 "  --ignore-depends=<package>,...\n"
 "                             Ignore dependencies involving <package>.\n"
+"  --overwrite-conffiles      Install package maintainer's 
configuration files\n"
 "  --force-...                Override problems (see --force-help).\n"
 "  --no-force-...|--refuse-...\n"
 "                             Stop when problems encountered.\n"
@@ -175,6 +176,7 @@ int f_pending=0, f_recursive=0, f_alsose
 int f_autodeconf=0, f_nodebsig=0;
 int f_triggers = 0;
 unsigned long f_debug=0;
+int f_overwriteconf=0;
 /* Change fc_overwrite to 1 to enable force-overwrite by default */
 int fc_downgrade=1, fc_configureany=0, fc_hold=0, 
fc_removereinstreq=0, fc_overwrite=0;
 int fc_removeessential=0, fc_conflicts=0, fc_depends=0, 
fc_dependsversion=0;
@@ -516,6 +518,7 @@ static const struct cmdinfo cmdinfos[]=
   { "admindir",          0,   1, NULL, &admindir, NULL,          0 },
   { "instdir",           0,   1, NULL, &instdir,  NULL,          0 },
   { "ignore-depends",    0,   1, NULL,          NULL,      
ignoredepends, 0 },
+  { "overwrite-conffiles", 0, 0, &f_overwriteconf, NULL,   NULL,    1 },
   { "force",             0,   2, NULL,          NULL,      
setforce,      1 },
   { "refuse",            0,   2, NULL,          NULL,      
setforce,      0 },
   { "no-force",          0,   2, NULL,          NULL,      
setforce,      0 },
diff -upr ./a/src/main.h ./b/src/main.h
--- ./a/src/main.h    2010-04-15 13:38:58.000000000 +0200
+++ ./b/src/main.h    2010-06-29 18:10:22.676904835 +0200
@@ -117,6 +117,7 @@ extern int f_pending, f_recursive, f_als
 extern int f_autodeconf, f_nodebsig;
 extern int f_triggers;
 extern unsigned long f_debug;
+extern int f_overwriteconf;
 extern int fc_downgrade, fc_configureany, fc_hold, fc_removereinstreq, 
fc_overwrite;
 extern int fc_removeessential, fc_conflicts, fc_depends, 
fc_dependsversion;
 extern int fc_breaks, fc_badpath, fc_overwritediverted, fc_architecture;