pkgadd: avoid fake installations if unpacking fails

This patch aborts the package installation and remove the package
from the database on any extraction error. This fixes FS#620.

I don't know why the extraction errors were ignored (even documented).
The initial commit already had this behaviour. Another odd thing
is that the install status of the package was commited to the database
before it was installed while there are exceptions used in pkg_install():
 - archive open error
 - empty archive
 - archive read error
Any of these errors will falsely mark the package as installed (maybe
not a big problem with upgrades).

To avoid breaking something (else), this fix kicks in
only with fresh installs (not upgrades).

Thanks Erich Eckner, for pointing out that the issue
is reproductible with a read-only destination. Otherwise,
I don't think I would have looked at this issue.

A test case is presented with the FS issue, just in case someone
who loves C++ enough to dig deeper or have more knowledge about
the history of this program would take a closer look.

3 files changed, 15 insertions, 4 deletions

diff --git a/pkgadd.cc b/pkgadd.cc
index 03cf0ec9..deeb50bc 100644
--- a/pkgadd.cc
+++ b/pkgadd.cc
@@ -103,7 +103,15 @@ void pkgadd::run(int argc, char** argv)
    
 		db_add_pkg(package.first, package.second);
 		db_commit();
-		pkg_install(o_package, keep_list, non_install_files);
+		try {
+			pkg_install(o_package, keep_list, non_install_files, installed);
+		} catch (runtime_error&) {
+			if (!installed) {
+				db_rm_pkg(package.first);
+				db_commit();
+				throw runtime_error("failed");
+			}
+		}
 		ldconfig();
 	}
 }
diff --git a/pkgutil.cc b/pkgutil.cc
index 87a4ffcc..926418cc 100644
--- a/pkgutil.cc
+++ b/pkgutil.cc
@@ -383,7 +383,7 @@ pair<string, pkgutil::pkginfo_t> pkgutil::pkg_open(const string& filename) const
 	return result;
 }
 
-void pkgutil::pkg_install(const string& filename, const set<string>& keep_list, const set<string>& non_install_list) const
+void pkgutil::pkg_install(const string& filename, const set<string>& keep_list, const set<string>& non_install_list, bool upgrade) const
 {
 	struct archive* archive;
 	struct archive_entry* entry;
@@ -435,9 +435,12 @@ void pkgutil::pkg_install(const string& filename, const set<string>& keep_list,
 
 		if (archive_read_extract(archive, entry, flags) != ARCHIVE_OK) {
 			// If a file fails to install we just print an error message and
-			// continue trying to install the rest of the package.
+			// continue trying to install the rest of the package,
+			// unless this is not an upgrade.
 			const char* msg = archive_error_string(archive);
 			cerr << utilname << ": could not install " + archive_filename << ": " << msg << endl;
+			if (!upgrade)
+				throw runtime_error("extract error: " + archive_filename + ": " + msg);
 			continue;
 		}
 
diff --git a/pkgutil.h b/pkgutil.h
index 4a4cabff..ce58f807 100644
--- a/pkgutil.h
+++ b/pkgutil.h
@@ -71,7 +71,7 @@ protected:
 
 	// Tar.gz
 	pair<string, pkginfo_t> pkg_open(const string& filename) const;
-	void pkg_install(const string& filename, const set<string>& keep_list, const set<string>& non_install_files) const;
+	void pkg_install(const string& filename, const set<string>& keep_list, const set<string>& non_install_files, bool upgrade) const;
 	void pkg_footprint(string& filename) const;
 	void ldconfig() const;