[pacman-dev] [PATCH] Allow query of file owners to work with non-existing files

[Vladimir Panteleev]

Previously, attempting to query the owner of a file owned by some
package but absent from the filesystem would fail. This could lead to
a small annoyance - if a user or misbehaving software accidentally
deleted a file owned by some package, and the user wishes to know
which package it belonged to so that it can be restored, pacman would
refuse to provide this information if the file no longer exists.

Thus, allow file owner query to continue if the file does not exist.
Print a warning in this situation and continue lookup using the exact
user-provided path.

Add test for this functionality accordingly.

Signed-off-by: Vladimir Panteleev <archlinux at thecybershadow.net>
---
 src/pacman/query.c            | 14 +++++++++++---
 test/pacman/tests/TESTS       |  1 +
 test/pacman/tests/query013.py | 10 ++++++++++
 3 files changed, 22 insertions(+), 3 deletions(-)
 create mode 100644 test/pacman/tests/query013.py

diff --git a/src/pacman/query.c b/src/pacman/query.c
index 024d3e21..bc27df8e 100644
--- a/src/pacman/query.c
+++ b/src/pacman/query.c
@@ -180,9 +180,16 @@ static int query_fileowner(alpm_list_t *targets)
 					goto targcleanup;
 				}
 			} else {
-				pm_printf(ALPM_LOG_ERROR, _("failed to read file '%s': %s\n"),
-						filename, strerror(errno));
-				goto targcleanup;
+				if (errno == ENOENT) {
+					pm_printf(ALPM_LOG_WARNING, _("file '%s' does not exist, not canonicalizing\n"),
+							filename);
+					strcpy(rpath, filename);
+					goto noent;
+				} else {
+					pm_printf(ALPM_LOG_ERROR, _("failed to read file '%s': %s\n"),
+							filename, strerror(errno));
+					goto targcleanup;
+				}
 			}
 		}
 
@@ -192,6 +199,7 @@ static int query_fileowner(alpm_list_t *targets)
 			goto targcleanup;
 		}
 
+noent:
 		if(strncmp(rpath, root, rootlen) != 0) {
 			/* file is outside root, we know nothing can own it */
 			pm_printf(ALPM_LOG_ERROR, _("No package owns %s\n"), filename);
diff --git a/test/pacman/tests/TESTS b/test/pacman/tests/TESTS
index 309eb17e..344b1b49 100644
--- a/test/pacman/tests/TESTS
+++ b/test/pacman/tests/TESTS
@@ -109,6 +109,7 @@ TESTS += test/pacman/tests/query007.py
 TESTS += test/pacman/tests/query010.py
 TESTS += test/pacman/tests/query011.py
 TESTS += test/pacman/tests/query012.py
+TESTS += test/pacman/tests/query013.py
 TESTS += test/pacman/tests/querycheck001.py
 TESTS += test/pacman/tests/querycheck002.py
 TESTS += test/pacman/tests/querycheck_fast_file_type.py
diff --git a/test/pacman/tests/query013.py b/test/pacman/tests/query013.py
new file mode 100644
index 00000000..b3c0a335
--- /dev/null
+++ b/test/pacman/tests/query013.py
@@ -0,0 +1,10 @@
+self.description = "Query ownership of non-existing file"
+
+sp = pmpkg("dummy", "1.0-1")
+sp.files = ["etc/config"]
+self.addpkg2db("local", sp)
+
+self.args = "-Qo %s/etc/config" % self.root
+
+self.addrule("PACMAN_RETCODE=0")
+self.addrule("PACMAN_OUTPUT=/etc/config is owned by dummy 1.0-1$")
-- 
2.13.3