[devel] %post-script prerequisites

["Alexey M. Tourbin" <at@altlinux.org>]

Когда в %post-скрипте пакета запускается программа, запакованная
в сам этот пакет, тогда некоторые зависимости Requires пакета нужно
продублировать в Requires(post).  Например, если в пакете libgtk+2
запускается программа gkt-update-icon-cache, то должна появиться
зависимость на новый пакет glib2 вида
Requires(post): libglib-2.0.so.0(GLIB_2.18).

Update of /people/at/packages/rpm.git

Changes statistics since `4.0.4-alt95.M41.4-7-g3de7779' follows:
 scripts/find-scriptlet-requires.in |   27 +++++++++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)

Changelog since `4.0.4-alt95.M41.4-7-g3de7779' follows:
commit 555b366b2df864b37878a989ce337078555316a4
Author: Alexey Tourbin <at@altlinux>
Date:   Wed Sep 24 12:17:39 2008 +0000

    find-scriptlet-requires: describe Requires(post) problem in %post-scripts

Full diff since `4.0.4-alt95.M41.4-7-g3de7779' follows:
diff --git a/scripts/find-scriptlet-requires.in b/scripts/find-scriptlet-requires.in
index 85d432e..6d37605 100755
--- a/scripts/find-scriptlet-requires.in
+++ b/scripts/find-scriptlet-requires.in
@@ -77,4 +77,31 @@ RunMethods req "$methods" RunMethod
 PrintDeps >"$workdir"/deps0
 if [ -s "$workdir"/deps0 ]; then
 	cat "$workdir"/deps0
+else
+	exit
 fi
+
+# Consider a program which is packaged into a package, and which gets
+# called in %post or %preun scriptlet of the package (e.g. in libgtk+2,
+# gtk-update-icon-cache might be called in %post-script).  Packaged
+# programs have "Requires" dependencies, and, for %post and %preun scripts,
+# the dependencies on packaged programs are optimized out (as well as other
+# dependencies provided by the package).  This is a problem: when executing
+# %post-script, its prerequisites might not be installed yet (e.g.
+# gtk-update-icon-cache requires recent glib2 version installed/upgraded
+# before libgtk+2).
+
+# The solution is: 1) to detect all packaged programs (and files), recursively,
+# which are used in %post-script; and 2) to find prerequisites for such files
+# and programs (which are not provided by the package itself), and add them to
+# Requires(post) dependencies.  Also, we want to ensure that 3) the list of
+# Requires(post) additional dependencies is only a subset of original Requires.
+
+# The above applies only to %post and %preun scriptlets.
+case "${script##*/}" in
+	.post:* | .preun:* ) ;;
+	*) exit ;;
+esac
+
+# The above applies only if packaged programs can be used in scripts.
+[ -s "$RPM_BUILD_ROOT/.files:${RPM_SUBPACKAGE_NAME:?}" ] || exit 0