v1-fix-broken-read_func-API.patch

diff --git a/src/bin/pg_dump/compress_gzip.c b/src/bin/pg_dump/compress_gzip.c
index 5a30ebf9bf5..8db121b94a3 100644
--- a/src/bin/pg_dump/compress_gzip.c
+++ b/src/bin/pg_dump/compress_gzip.c
@@ -251,14 +251,14 @@ InitCompressorGzip(CompressorState *cs,
  *----------------------
  */
 
-static bool
-Gzip_read(void *ptr, size_t size, size_t *rsize, CompressFileHandle *CFH)
+static size_t
+Gzip_read(void *ptr, size_t size, CompressFileHandle *CFH)
 {
 	gzFile		gzfp = (gzFile) CFH->private_data;
 	int			gzret;
 
 	gzret = gzread(gzfp, ptr, size);
-	if (gzret <= 0 && !gzeof(gzfp))
+	if (gzret < 0)
 	{
 		int			errnum;
 		const char *errmsg = gzerror(gzfp, &errnum);
@@ -267,10 +267,7 @@ Gzip_read(void *ptr, size_t size, size_t *rsize, CompressFileHandle *CFH)
 				 errnum == Z_ERRNO ? strerror(errno) : errmsg);
 	}
 
-	if (rsize)
-		*rsize = (size_t) gzret;
-
-	return true;
+	return (size_t) gzret;
 }
 
 static bool
@@ -278,7 +275,7 @@ Gzip_write(const void *ptr, size_t size, CompressFileHandle *CFH)
 {
 	gzFile		gzfp = (gzFile) CFH->private_data;
 
-	return gzwrite(gzfp, ptr, size) > 0;
+	return gzwrite(gzfp, ptr, size) == size;
 }
 
 static int
diff --git a/src/bin/pg_dump/compress_io.h b/src/bin/pg_dump/compress_io.h
index db9b38744c8..dad0c91fec5 100644
--- a/src/bin/pg_dump/compress_io.h
+++ b/src/bin/pg_dump/compress_io.h
@@ -123,21 +123,23 @@ struct CompressFileHandle
 									CompressFileHandle *CFH);
 
 	/*
-	 * Read 'size' bytes of data from the file and store them into 'ptr'.
-	 * Optionally it will store the number of bytes read in 'rsize'.
+	 * Read up to 'size' bytes of data from the file and store them into
+	 * 'ptr'.
 	 *
-	 * Returns true on success and throws an internal error otherwise.
+	 * Returns number of bytes read (this might be less than 'size' if EOF was
+	 * reached).  Throws error for error conditions other than EOF.
 	 */
-	bool		(*read_func) (void *ptr, size_t size, size_t *rsize,
+	size_t		(*read_func) (void *ptr, size_t size,
 							  CompressFileHandle *CFH);
 
 	/*
 	 * Write 'size' bytes of data into the file from 'ptr'.
 	 *
-	 * Returns true on success and false on error.
+	 * Returns true on success and false on error (it is caller's
+	 * responsibility to deal with error conditions).
 	 */
 	bool		(*write_func) (const void *ptr, size_t size,
-							   struct CompressFileHandle *CFH);
+							   CompressFileHandle *CFH);
 
 	/*
 	 * Read at most size - 1 characters from the compress file handle into
diff --git a/src/bin/pg_dump/compress_lz4.c b/src/bin/pg_dump/compress_lz4.c
index e99f0cad71f..c94f9dcd4cf 100644
--- a/src/bin/pg_dump/compress_lz4.c
+++ b/src/bin/pg_dump/compress_lz4.c
@@ -583,6 +583,7 @@ LZ4Stream_write(const void *ptr, size_t size, CompressFileHandle *CFH)
 			return false;
 		}
 
+		errno = 0;
 		if (fwrite(state->buffer, 1, status, state->fp) != status)
 		{
 			errno = (errno) ? errno : ENOSPC;
@@ -598,8 +599,8 @@ LZ4Stream_write(const void *ptr, size_t size, CompressFileHandle *CFH)
 /*
  * fread() equivalent implementation for LZ4 compressed files.
  */
-static bool
-LZ4Stream_read(void *ptr, size_t size, size_t *rsize, CompressFileHandle *CFH)
+static size_t
+LZ4Stream_read(void *ptr, size_t size, CompressFileHandle *CFH)
 {
 	LZ4State   *state = (LZ4State *) CFH->private_data;
 	int			ret;
@@ -607,10 +608,7 @@ LZ4Stream_read(void *ptr, size_t size, size_t *rsize, CompressFileHandle *CFH)
 	if ((ret = LZ4Stream_read_internal(state, ptr, size, false)) < 0)
 		pg_fatal("could not read from input file: %s", LZ4Stream_get_error(CFH));
 
-	if (rsize)
-		*rsize = (size_t) ret;
-
-	return true;
+	return (size_t) ret;
 }
 
 /*
diff --git a/src/bin/pg_dump/compress_none.c b/src/bin/pg_dump/compress_none.c
index 3fc89c99854..4924935a5bd 100644
--- a/src/bin/pg_dump/compress_none.c
+++ b/src/bin/pg_dump/compress_none.c
@@ -83,23 +83,17 @@ InitCompressorNone(CompressorState *cs,
  * Private routines
  */
 
-static bool
-read_none(void *ptr, size_t size, size_t *rsize, CompressFileHandle *CFH)
+static size_t
+read_none(void *ptr, size_t size, CompressFileHandle *CFH)
 {
 	FILE	   *fp = (FILE *) CFH->private_data;
 	size_t		ret;
 
-	if (size == 0)
-		return true;
-
 	ret = fread(ptr, 1, size, fp);
-	if (ret != size && !feof(fp))
+	if (ferror(fp))
 		pg_fatal("could not read from input file: %m");
 
-	if (rsize)
-		*rsize = ret;
-
-	return true;
+	return ret;
 }
 
 static bool
diff --git a/src/bin/pg_dump/compress_zstd.c b/src/bin/pg_dump/compress_zstd.c
index cb595b10c2d..8f718212d9f 100644
--- a/src/bin/pg_dump/compress_zstd.c
+++ b/src/bin/pg_dump/compress_zstd.c
@@ -258,8 +258,8 @@ InitCompressorZstd(CompressorState *cs,
  * Compressed stream API
  */
 
-static bool
-Zstd_read(void *ptr, size_t size, size_t *rdsize, CompressFileHandle *CFH)
+static size_t
+Zstd_read(void *ptr, size_t size, CompressFileHandle *CFH)
 {
 	ZstdCompressorState *zstdcs = (ZstdCompressorState *) CFH->private_data;
 	ZSTD_inBuffer *input = &zstdcs->input;
@@ -292,6 +292,9 @@ Zstd_read(void *ptr, size_t size, size_t *rdsize, CompressFileHandle *CFH)
 		if (input->pos == input->size)
 		{
 			cnt = fread(unconstify(void *, input->src), 1, input_allocated_size, zstdcs->fp);
+			if (ferror(zstdcs->fp))
+				pg_fatal("could not read from input file: %m");
+
 			input->size = cnt;
 
 			Assert(cnt <= input_allocated_size);
@@ -320,10 +323,7 @@ Zstd_read(void *ptr, size_t size, size_t *rdsize, CompressFileHandle *CFH)
 			break;				/* We read all the data that fits */
 	}
 
-	if (rdsize != NULL)
-		*rdsize = output->pos;
-
-	return true;
+	return output->pos;
 }
 
 static bool
@@ -358,22 +358,16 @@ Zstd_write(const void *ptr, size_t size, CompressFileHandle *CFH)
 		}
 	}
 
-	return size;
+	return true;
 }
 
 static int
 Zstd_getc(CompressFileHandle *CFH)
 {
-	ZstdCompressorState *zstdcs = (ZstdCompressorState *) CFH->private_data;
-	int			ret;
+	unsigned char ret;
 
-	if (CFH->read_func(&ret, 1, NULL, CFH) != 1)
-	{
-		if (feof(zstdcs->fp))
-			pg_fatal("could not read from input file: end of file");
-		else
-			pg_fatal("could not read from input file: %m");
-	}
+	if (CFH->read_func(&ret, 1, CFH) != 1)
+		pg_fatal("could not read from input file: end of file");
 	return ret;
 }
 
@@ -390,11 +384,7 @@ Zstd_gets(char *buf, int len, CompressFileHandle *CFH)
 	 */
 	for (i = 0; i < len - 1; ++i)
 	{
-		size_t		readsz;
-
-		if (!CFH->read_func(&buf[i], 1, &readsz, CFH))
-			break;
-		if (readsz != 1)
+		if (CFH->read_func(&buf[i], 1, CFH) != 1)
 			break;
 		if (buf[i] == '\n')
 		{
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index bc2a2fb4797..eb2ce8d5a6c 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -351,7 +351,7 @@ _EndData(ArchiveHandle *AH, TocEntry *te)
 static void
 _PrintFileData(ArchiveHandle *AH, char *filename)
 {
-	size_t		cnt = 0;
+	size_t		cnt;
 	char	   *buf;
 	size_t		buflen;
 	CompressFileHandle *CFH;
@@ -366,7 +366,7 @@ _PrintFileData(ArchiveHandle *AH, char *filename)
 	buflen = DEFAULT_IO_BUFFER_SIZE;
 	buf = pg_malloc(buflen);
 
-	while (CFH->read_func(buf, buflen, &cnt, CFH) && cnt > 0)
+	while ((cnt = CFH->read_func(buf, buflen, CFH)) > 0)
 	{
 		ahwrite(buf, 1, cnt, AH);
 	}
@@ -531,10 +531,10 @@ _ReadBuf(ArchiveHandle *AH, void *buf, size_t len)
 	CompressFileHandle *CFH = ctx->dataFH;
 
 	/*
-	 * If there was an I/O error, we already exited in readF(), so here we
-	 * exit on short reads.
+	 * We do not expect a short read, so fail if we get one.  The read_func
+	 * already dealt with any outright I/O error.
 	 */
-	if (!CFH->read_func(buf, len, NULL, CFH))
+	if (CFH->read_func(buf, len, CFH) != len)
 		pg_fatal("could not read from input file: end of file");
 }