Change return value of gdbm_close and gdbm_sync

* src/gdbm.h.in (gdbm_close, gdbm_sync): Return int
(GDBM_FILE_CLOSE_ERROR, GDBM_FILE_SYNC_ERROR): New error codes.
* src/gdbmclose.c (gdbm_close): Return 0 on success, -1 on failure.
Set gdbm_errno and errno.
* src/gdbmsync.c (gdbm_sync): Likewise.
* src/gdbmerrno.c: Handle new error codes.
* src/mmap.c (_gdbm_mapped_sync): Set gdbm_errno.
* src/proto.h (gdbm_file_sync): Set gdbm_errno.

* doc/gdbm.3: Document changes.
* doc/gdbm.texi: Document changes.
* NEWS: Document changes.
* configure.ac: Set patchlevel.

* tests/Makefile.am: Add new test.
* tests/testsuite.at: Add new test.
* tests/closerr.at: New test case.
* tests/closerr.c: New test program.
* tests/gtdel.c: Check gdbm_close return.
* tests/gtdump.c: Likewise.
* tests/gtfetch.c: Likewise.
* tests/gtload.c: Likewise.
* tests/gtopt.c: Likewise.
* tests/gtrecover.c: Likewise.

2 files changed, 17 insertions, 9 deletions

diff --git a/doc/gdbm.3 b/doc/gdbm.3
index 6107d9a..d803748 100644
--- a/doc/gdbm.3
+++ b/doc/gdbm.3
@@ -14,5 +14,5 @@
 .\" You should have received a copy of the GNU General Public License
 .\" along with GDBM. If not, see <http://www.gnu.org/licenses/>. */
-.TH GDBM 3 "July 8, 2016" "GDBM" "GDBM User Reference"
+.TH GDBM 3 "July 1, 2018" "GDBM" "GDBM User Reference"
 .SH NAME
 GDBM \- The GNU database manager.  Includes \fBdbm\fR and \fBndbm\fR
@@ -32,5 +32,5 @@ compatibility.
 .BI "void (*" fatal_func ")(const char *))";
 .br
-.BI "void gdbm_close (GDBM_FILE " dbf ");"
+.BI "int gdbm_close (GDBM_FILE " dbf ");"
 .br
 .BI "int gdbm_store (GDBM_FILE " dbf ", datum " key ", datum " content ", int " flag );
@@ -46,5 +46,5 @@ compatibility.
 .BI "int gdbm_reorganize (GDBM_FILE " dbf ");"
 .br
-.BI "void gdbm_sync (GDBM_FILE " dbf ");"
+.BI "int gdbm_sync (GDBM_FILE " dbf ");"
 .br
 .BI "int gdbm_exists (GDBM_FILE " dbf ", datum " key );
@@ -184,5 +184,5 @@ It is important that every file opened is also closed.  This is needed to
 update the reader/writer count on the file.  This is done by:
 
-.BI "void gdbm_close (GDBM_FILE " dbf ");"
+.BI "int gdbm_close (GDBM_FILE " dbf ");"
 
 The database is used by 3 primary routines.  The first stores data in the
@@ -309,5 +309,5 @@ The following routine can be used to guarantee that the database is
 physically written to the disk file.
 
-.BI "void gdbm_sync (GDBM_FILE " dbf ");"
+.BI "int gdbm_sync (GDBM_FILE " dbf ");"
 
 It will not return until the disk file state is syncronized with the
diff --git a/doc/gdbm.texi b/doc/gdbm.texi
index b5ba53d..4a0b1a7 100644
--- a/doc/gdbm.texi
+++ b/doc/gdbm.texi
@@ -216,5 +216,5 @@ contains a definition of these functions.
 
 GDBM_FILE gdbm_open(name, block_size, flags, mode, fatal_func);
-void gdbm_close(dbf);
+int gdbm_close(dbf);
 int gdbm_store(dbf, key, content, flag);
 datum gdbm_fetch(dbf, key);
@@ -223,5 +223,5 @@ datum gdbm_firstkey(dbf);
 datum gdbm_nextkey(dbf, key);
 int gdbm_reorganize(dbf);
-void gdbm_sync(dbf);
+int gdbm_sync(dbf);
 int gdbm_exists(dbf, key);
 char *gdbm_strerror(errno);
@@ -370,5 +370,5 @@ It is important that every file opened is also closed.  This is needed to
 update the reader/writer count on the file:
 
-@deftypefn {gdbm interface} void gdbm_close (GDBM_FILE @var{dbf})
+@deftypefn {gdbm interface} int gdbm_close (GDBM_FILE @var{dbf})
 This function closes the @code{gdbm} file and frees all memory
 associated with it.  The parameter is:
@@ -378,4 +378,8 @@ associated with it.  The parameter is:
 The pointer returned by @code{gdbm_open}.
 @end table
+
+@code{Gdbm_close} returns 0 on success. On error, it sets
+@code{gdbm_errno} and system @code{errno} variables to the codes
+describing the error and returns -1.
 @end deftypefn
 
@@ -679,5 +683,5 @@ make sure the disk version of the database has been completely updated
 with all changes to the current time.
 
-@deftypefn {gdbm interface} void gdbm_sync (GDBM_FILE @var{dbf})
+@deftypefn {gdbm interface} int gdbm_sync (GDBM_FILE @var{dbf})
 Synchronizes the changes in @var{dbf} with its disk file.  The
 parameter is a pointer returned by @code{gdbm_open}.
@@ -688,4 +692,8 @@ The @code{gdbm_close} function automatically calls the equivalent of
 @code{gdbm_sync} so no call is needed if the database is to be closed
 immediately after the set of changes have been made.
+
+@code{Gdbm_sync} returns 0 on success. On error, it sets
+@code{gdbm_errno} and system @code{errno} variables to the codes
+describing the error and returns -1.
 @end deftypefn