diff --git a/src/bin/pg_dump/compress_gzip.c b/src/bin/pg_dump/compress_gzip.c
index cec0b41fcea..63dfd9668c1 100644
--- a/src/bin/pg_dump/compress_gzip.c
+++ b/src/bin/pg_dump/compress_gzip.c
@@ -33,8 +33,73 @@ typedef struct GzipCompressorState
} GzipCompressorState;
/* Private routines that support gzip compressed data I/O */
+static void DeflateCompressorInit(CompressorState *cs);
+static void DeflateCompressorEnd(ArchiveHandle *AH, CompressorState *cs);
+static void DeflateCompressorCommon(ArchiveHandle *AH, CompressorState *cs,
+ bool flush);
+static void EndCompressorGzip(ArchiveHandle *AH, CompressorState *cs);
+static void WriteDataToArchiveGzip(ArchiveHandle *AH, CompressorState *cs,
+ const void *data, size_t dLen);
+static void ReadDataFromArchiveGzip(ArchiveHandle *AH, CompressorState *cs);
+
static void
-DeflateCompressorGzip(ArchiveHandle *AH, CompressorState *cs, bool flush)
+DeflateCompressorInit(CompressorState *cs)
+{
+ GzipCompressorState *gzipcs;
+ z_streamp zp;
+
+ gzipcs = (GzipCompressorState *) pg_malloc0(sizeof(GzipCompressorState));
+ zp = gzipcs->zp = (z_streamp) pg_malloc(sizeof(z_stream));
+ zp->zalloc = Z_NULL;
+ zp->zfree = Z_NULL;
+ zp->opaque = Z_NULL;
+
+ /*
+ * outsize is the buffer size we tell zlib it can output to. We actually
+ * allocate one extra byte because some routines want to append a trailing
+ * zero byte to the zlib output.
+ */
+ gzipcs->outsize = DEFAULT_IO_BUFFER_SIZE;
+ gzipcs->outbuf = pg_malloc(gzipcs->outsize + 1);
+
+ /* -Z 0 uses the "None" compressor -- not zlib with no compression */
+ Assert(cs->compression_spec.level != 0);
+
+ if (deflateInit(zp, cs->compression_spec.level) != Z_OK)
+ pg_fatal("could not initialize compression library: %s", zp->msg);
+
+ /* Just be paranoid - maybe End is called after Start, with no Write */
+ zp->next_out = gzipcs->outbuf;
+ zp->avail_out = gzipcs->outsize;
+
+ /* Keep track of gzipcs */
+ cs->private_data = gzipcs;
+}
+
+static void
+DeflateCompressorEnd(ArchiveHandle *AH, CompressorState *cs)
+{
+ GzipCompressorState *gzipcs = (GzipCompressorState *) cs->private_data;
+ z_streamp zp;
+
+ zp = gzipcs->zp;
+ zp->next_in = NULL;
+ zp->avail_in = 0;
+
+ /* Flush any remaining data from zlib buffer */
+ DeflateCompressorCommon(AH, cs, true);
+
+ if (deflateEnd(zp) != Z_OK)
+ pg_fatal("could not close compression stream: %s", zp->msg);
+
+ pg_free(gzipcs->outbuf);
+ pg_free(gzipcs->zp);
+ pg_free(gzipcs);
+ cs->private_data = NULL;
+}
+
+static void
+DeflateCompressorCommon(ArchiveHandle *AH, CompressorState *cs, bool flush)
{
GzipCompressorState *gzipcs = (GzipCompressorState *) cs->private_data;
z_streamp zp = gzipcs->zp;
@@ -78,27 +143,9 @@ DeflateCompressorGzip(ArchiveHandle *AH, CompressorState *cs, bool flush)
static void
EndCompressorGzip(ArchiveHandle *AH, CompressorState *cs)
{
- GzipCompressorState *gzipcs = (GzipCompressorState *) cs->private_data;
- z_streamp zp;
-
- if (gzipcs->zp)
- {
- zp = gzipcs->zp;
- zp->next_in = NULL;
- zp->avail_in = 0;
-
- /* Flush any remaining data from zlib buffer */
- DeflateCompressorGzip(AH, cs, true);
-
- if (deflateEnd(zp) != Z_OK)
- pg_fatal("could not close compression stream: %s", zp->msg);
-
- pg_free(gzipcs->outbuf);
- pg_free(gzipcs->zp);
- }
-
- pg_free(gzipcs);
- cs->private_data = NULL;
+ /* If deflation was initialized, finalize it */
+ if (cs->private_data)
+ DeflateCompressorEnd(AH, cs);
}
static void
@@ -106,41 +153,10 @@ WriteDataToArchiveGzip(ArchiveHandle *AH, CompressorState *cs,
const void *data, size_t dLen)
{
GzipCompressorState *gzipcs = (GzipCompressorState *) cs->private_data;
- z_streamp zp;
-
- if (!gzipcs->zp)
- {
- zp = gzipcs->zp = (z_streamp) pg_malloc(sizeof(z_stream));
- zp->zalloc = Z_NULL;
- zp->zfree = Z_NULL;
- zp->opaque = Z_NULL;
-
- /*
- * outsize is the buffer size we tell zlib it can output to. We
- * actually allocate one extra byte because some routines want to
- * append a trailing zero byte to the zlib output.
- */
- gzipcs->outsize = DEFAULT_IO_BUFFER_SIZE;
- gzipcs->outbuf = pg_malloc(gzipcs->outsize + 1);
-
- /*
- * A level of zero simply copies the input one block at the time. This
- * is probably not what the user wanted when calling this interface.
- */
- if (cs->compression_spec.level == 0)
- pg_fatal("requested to compress the archive yet no level was specified");
-
- if (deflateInit(zp, cs->compression_spec.level) != Z_OK)
- pg_fatal("could not initialize compression library: %s", zp->msg);
-
- /* Just be paranoid - maybe End is called after Start, with no Write */
- zp->next_out = gzipcs->outbuf;
- zp->avail_out = gzipcs->outsize;
- }
gzipcs->zp->next_in = (void *) unconstify(void *, data);
gzipcs->zp->avail_in = dLen;
- DeflateCompressorGzip(AH, cs, false);
+ DeflateCompressorCommon(AH, cs, false);
}
static void
@@ -214,17 +230,19 @@ void
InitCompressorGzip(CompressorState *cs,
const pg_compress_specification compression_spec)
{
- GzipCompressorState *gzipcs;
-
cs->readData = ReadDataFromArchiveGzip;
cs->writeData = WriteDataToArchiveGzip;
cs->end = EndCompressorGzip;
cs->compression_spec = compression_spec;
- gzipcs = (GzipCompressorState *) pg_malloc0(sizeof(GzipCompressorState));
-
- cs->private_data = gzipcs;
+ /*
+ * If the caller has defined a write function, prepare the necessary
+ * state. Note that if the data is empty, End may be called immediately
+ * after Init, without ever calling Write.
+ */
+ if (cs->writeF)
+ DeflateCompressorInit(cs);
}
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index a22f27f300f..42215f82f7a 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -1265,6 +1265,29 @@ my %tests = (
},
},
+ 'LO create (with no data)' => {
+ create_sql =>
+ 'SELECT pg_catalog.lo_create(0);',
+ regexp => qr/^
+ \QSELECT pg_catalog.lo_open\E \('\d+',\ \d+\);\n
+ \QSELECT pg_catalog.lo_close(0);\E
+ /xm,
+ like => {
+ %full_runs,
+ column_inserts => 1,
+ data_only => 1,
+ inserts => 1,
+ section_data => 1,
+ test_schema_plus_large_objects => 1,
+ },
+ unlike => {
+ binary_upgrade => 1,
+ no_large_objects => 1,
+ schema_only => 1,
+ section_pre_data => 1,
+ },
+ },
+
'COMMENT ON DATABASE postgres' => {
regexp => qr/^COMMENT ON DATABASE postgres IS .+;/m,