[pacman-dev] [PATCH] Fix double close of the lock file

[Jonathan Conder]

According to FOPEN(3), using fclose on an fdopen'd file stream also
closes the underlying file descriptor. This happened in _alpm_lckmk
(util.c), which meant that when alpm_trans_release closed it again, the
log file (which reused the original file descriptor) was closed instead.

Signed-off-by: Jonathan Conder <jonno.conder at gmail.com>
---
 lib/libalpm/handle.c |    1 -
 lib/libalpm/handle.h |    2 +-
 lib/libalpm/trans.c  |   13 +++++--------
 lib/libalpm/util.c   |    7 +++----
 lib/libalpm/util.h   |    2 +-
 5 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/lib/libalpm/handle.c b/lib/libalpm/handle.c
index aa34cf4..8f44e94 100644
--- a/lib/libalpm/handle.c
+++ b/lib/libalpm/handle.c
@@ -49,7 +49,6 @@ pmhandle_t *_alpm_handle_new()
 	ALPM_LOG_FUNC;
 
 	CALLOC(handle, 1, sizeof(pmhandle_t), RET_ERR(PM_ERR_MEMORY, NULL));
-	handle->lckfd = -1;
 
 	return(handle);
 }
diff --git a/lib/libalpm/handle.h b/lib/libalpm/handle.h
index 1834994..6884666 100644
--- a/lib/libalpm/handle.h
+++ b/lib/libalpm/handle.h
@@ -34,7 +34,7 @@ typedef struct _pmhandle_t {
 	pmdb_t *db_local;       /* local db pointer */
 	alpm_list_t *dbs_sync;  /* List of (pmdb_t *) */
 	FILE *logstream;        /* log file stream pointer */
-	int lckfd;              /* lock file descriptor if one exists */
+	FILE *lckstream;        /* lock file stream pointer if one exists */
 	pmtrans_t *trans;
 
 	/* callback functions */
diff --git a/lib/libalpm/trans.c b/lib/libalpm/trans.c
index 02612ec..e13a7b2 100644
--- a/lib/libalpm/trans.c
+++ b/lib/libalpm/trans.c
@@ -73,8 +73,8 @@ int SYMEXPORT alpm_trans_init(pmtransflag_t flags,
 
 	/* lock db */
 	if(!(flags & PM_TRANS_FLAG_NOLOCK)) {
-		handle->lckfd = _alpm_lckmk();
-		if(handle->lckfd == -1) {
+		handle->lckstream = _alpm_lckmk();
+		if(handle->lckstream == NULL) {
 			RET_ERR(PM_ERR_HANDLE_LOCK, -1);
 		}
 	}
@@ -260,12 +260,9 @@ int SYMEXPORT alpm_trans_release()
 
 	/* unlock db */
 	if(!nolock_flag) {
-		if(handle->lckfd != -1) {
-			int fd;
-			do {
-				fd = close(handle->lckfd);
-			} while(fd == -1 && errno == EINTR);
-			handle->lckfd = -1;
+		if(handle->lckstream != NULL) {
+			fclose(handle->lckstream);
+			handle->lckstream = NULL;
 		}
 		if(_alpm_lckrm()) {
 			_alpm_log(PM_LOG_WARNING, _("could not remove lock file %s\n"),
diff --git a/lib/libalpm/util.c b/lib/libalpm/util.c
index 32eaa44..4d152ee 100644
--- a/lib/libalpm/util.c
+++ b/lib/libalpm/util.c
@@ -197,7 +197,7 @@ char *_alpm_strtrim(char *str)
 }
 
 /* Create a lock file */
-int _alpm_lckmk()
+FILE *_alpm_lckmk()
 {
 	int fd;
 	char *dir, *ptr;
@@ -220,10 +220,9 @@ int _alpm_lckmk()
 		fprintf(f, "%ld\n", (long)getpid());
 		fflush(f);
 		fsync(fd);
-		fclose(f);
-		return(fd);
+		return(f);
 	}
-	return(-1);
+	return(NULL);
 }
 
 /* Remove a lock file */
diff --git a/lib/libalpm/util.h b/lib/libalpm/util.h
index 8a3154a..edd51d5 100644
--- a/lib/libalpm/util.h
+++ b/lib/libalpm/util.h
@@ -62,7 +62,7 @@ int _alpm_makepath(const char *path);
 int _alpm_makepath_mode(const char *path, mode_t mode);
 int _alpm_copyfile(const char *src, const char *dest);
 char *_alpm_strtrim(char *str);
-int _alpm_lckmk();
+FILE *_alpm_lckmk();
 int _alpm_lckrm();
 int _alpm_unpack_single(const char *archive, const char *prefix, const char *fn);
 int _alpm_unpack(const char *archive, const char *prefix, alpm_list_t *list, int breakfirst);
-- 
1.7.4