Bug #275945 - Add a new --avoid-update which tries to avoid updating packages

which possible. Thanks to Sebastian Mingramm (few) <s.mingramm@gmx.de> for
this patch.

svn path=/main/trunk/; revision=13745

4 files changed, 34 insertions, 0 deletions

diff --git a/man/emerge.1 b/man/emerge.1
index df054c9e9..a1dbcde73 100644
--- a/man/emerge.1
+++ b/man/emerge.1
@@ -90,6 +90,15 @@ option if you want to install a tbz2\fR.  The packages are added
 to the \fBworld\fR file at the end, so that they are considered for
 later updating.
 .TP
+.BR "\-\-avoid\-update "
+Tries to prevent package updates. This may not always be
+possible since new packages or new dependencies due to USE
+flag changes may require a newer version of an installed
+package. Furthermore, this option may lead to slot conflicts
+(Multiple package instances within a single package slot
+have been pulled into the dependency graph). It is not
+possible to use this option in such a case.
+.TP
 .BR "\-\-clean " (\fB\-c\fR)
 Cleans up the system by examining the installed packages and removing older
 packages.  This is accomplished by looking at each installed package and separating
@@ -364,6 +373,9 @@ A USE flag was turned off for a package.
 
 USE flags may be toggled by your profile as well as your USE and package.use
 settings.
+
+\fB\-\-avoid\-update\fR may prevent updates of installed packages without 
+use flag changes. Note that \fB\-\-avoid-\update\fR may lead to slot conflicts.
 .TP
 .BR "\-\-noconfmem"
 Causes portage to disregard merge records indicating that a config file
diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 25e385521..de097c419 100644
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -2091,6 +2091,11 @@ class depgraph(object):
 				break
 
 		if len(matched_packages) > 1:
+			if "--avoid-update" in self.myopts:
+				for pkg in matched_packages:
+					if pkg.installed:
+						return pkg, existing_node
+
 			bestmatch = portage.best(
 				[pkg.cpv for pkg in matched_packages])
 			matched_packages = [pkg for pkg in matched_packages \
diff --git a/pym/_emerge/help.py b/pym/_emerge/help.py
index 950692136..1f4b5201e 100644
--- a/pym/_emerge/help.py
+++ b/pym/_emerge/help.py
@@ -235,6 +235,17 @@ def help(myaction,myopts,havecolor=1):
 		print "              to the prompt, so an accidental press of the \"Enter\" key at any"
 		print "              time prior to the prompt will be interpreted as a choice!"
 		print
+		print "       "+green("--avoid-update")
+		desc = "Tries to prevent package updates. This may not always be" + \
+			" possible since new packages or new dependencies due to USE" + \
+			" flag changes may require a newer version of an installed" + \
+			" package. Furthermore, this option may lead to slot conflicts" + \
+			" (Multiple package instances within a single package slot" + \
+			" have been pulled into the dependency graph). It is not" + \
+			" possible to use this option in such a case."
+		for line in wrap(desc, desc_width):
+			print desc_indent + line
+		print
 		print "       "+green("--buildpkg")+" ("+green("-b")+" short option)"
 		desc = "Tells emerge to build binary packages for all ebuilds processed in" + \
 			" addition to actually merging the packages. Useful for maintainers" + \
diff --git a/pym/_emerge/main.py b/pym/_emerge/main.py
index f73bc6db4..087493c4d 100644
--- a/pym/_emerge/main.py
+++ b/pym/_emerge/main.py
@@ -65,6 +65,7 @@ options=[
 "--searchdesc",   "--selective",
 "--skipfirst",
 "--tree",
+"--avoid-update",
 "--update",
 "--usepkg",       "--usepkgonly",
 "--verbose",
@@ -1060,6 +1061,11 @@ def emerge_main():
 			noiselevel=-1)
 		return 1
 
+	if "--avoid-update" in myopts and "--update" in myopts:
+		writemsg("!!! conflicting options given: " + \
+			"--update and --avoid-update\n", noiselevel=-1)
+		return 1
+
 	if settings.get("PORTAGE_DEBUG", "") == "1":
 		spinner.update = spinner.update_quiet
 		portage.debug=1