Bug#293838: [PATCH] Intra-source file-conflicts

[Niels Thykier <niels@thykier.net>]

tags 293838 patch
thanks

Hi,

I have made a patch against master that attempts to find file conflicts.
 It does not handle diverts (which will be false-positives) nor
conflicts on Provides (probably it should).
  So far it breaks at least 5 tests (ocmal-general, 2 files ones, a menu
test and one of the legacy tests), which all appears to actually have a
file-conflict.

Comments and corrections welcome.  :)

~Niels

>From 1af0caded763dcc9e751de666a7b79440a387a7e Mon Sep 17 00:00:00 2001
From: Niels Thykier <niels@thykier.net>
Date: Sun, 20 Nov 2011 00:46:19 +0100
Subject: [PATCH 2/2] Implemented a simple file-conflict check in group-checks

Signed-off-by: Niels Thykier <niels@thykier.net>
---
 checks/group-checks      |   50 +++++++++++++++++++++++++++++++++++++++++++++-
 checks/group-checks.desc |   11 ++++++++++
 2 files changed, 60 insertions(+), 1 deletions(-)

diff --git a/checks/group-checks b/checks/group-checks
index 13e0365..ccf6d3b 100644
--- a/checks/group-checks
+++ b/checks/group-checks
@@ -47,8 +47,11 @@ my @nodes = ();
 my %edges = ();
 my $sccs;
 my $ginfo = $group->info;
+my @procs = $group->get_processables ('binary');
 
-foreach my $proc ($group->get_processables('binary')) {
+_check_file_overlap (@procs);
+
+foreach my $proc (@procs) {
     my $deps = $ginfo->direct_dependencies ($proc);
     if (scalar @$deps > 0) {
         # it depends on another package - it can cause
@@ -96,6 +99,51 @@ sub _check_priorities {
     }
 }
 
+sub _check_file_overlap {
+    my (@procs) = @_;
+    # Sort them for stable output
+    my @sorted = sort { $a->pkg_name cmp $b->pkg_name } @procs;
+    for (my $i = 0 ; $i < scalar @sorted ; $i++) {
+        my $proc = $sorted[$i];
+        my $pinfo = $proc->info;
+        for (my $j = $i ; $j < scalar @sorted ; $j++) {
+            my $other = $sorted[$j];
+            my $oinfo = $other->info;
+            # poor man's "Multi-arch: same" work-around.
+            next if $proc->pkg_name eq $other->pkg_name;
+
+            # $other conflicts/replaces with $proc
+            next if $oinfo->relation ('conflicts')->implies ($proc->pkg_name);
+            next if $oinfo->relation ('replaces')->implies ($proc->pkg_name);
+
+            # $proc conflicts/replaces with $other
+            next if $pinfo->relation ('conflicts')->implies ($other->pkg_name);
+            next if $pinfo->relation ('replaces')->implies ($other->pkg_name);
+
+            _overlap_check ($proc, $pinfo, $other, $oinfo);
+        }
+    }
+}
+
+sub _overlap_check {
+    my ($a_proc, $a_info, $b_proc, $b_info) = @_;
+    my $b_index = $b_info->index;
+    foreach my $raw (@{ $a_info->sorted_index }) {
+        my $file;
+        my $a_file;
+        my $b_file;
+        next unless $raw;
+        $file = $raw; # copy, because we have to modifiy it
+        $file =~ s,/$,,o;
+        $b_file = $b_index->{$file} // $b_index->{"$file/"};
+        if ($b_file) {
+            $a_file = $a_info->index->{$file} // $a_info->index->{"$file/"};
+            next if $a_file->{type} eq $b_file->{type} && $a_file->{type} eq 'd';
+            tag 'binaries-have-file-conflict', $a_proc->pkg_name, $b_proc->pkg_name, $file;
+        }
+    }
+}
+
 ## Encapsulate Tarjan's algorithm in an class/object to keep
 ## the run sub somewhat sane.
 package Lintian::group_checks::Graph;
diff --git a/checks/group-checks.desc b/checks/group-checks.desc
index b31ed54..4f71c6b 100644
--- a/checks/group-checks.desc
+++ b/checks/group-checks.desc
@@ -33,3 +33,14 @@ Info: The package depends on a package with lower priority than
  package.  A full check of all dependencies built from different
  source packages is beyond the scope of Lintian.  The depcheck service
  can do this.
+
+Tag: binaries-have-file-conflict
+Severity: normal
+Certainty: possible
+Experimental: no
+Info: The binaries appears to have overlapping files without proper
+ conflicts relation.
+ .
+ Note the check is completely based on the file index for the
+ packages.  Possible known false-positives include dpkg-diverts in
+ maintainer scripts.
-- 
1.7.7.1