[PATCH 12/22] reftable/reader: handle allocation failures in `reader_init_iter()`

[Patrick Steinhardt <ps@pks.im>]

Handle allocation failures in `reader_init_iter()`. This requires us to
also adapt `reftable_reader_init_*_iterator()` to bubble up the new
error codes. Adapt callers accordingly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 reftable/merged.c                   |  4 +++-
 reftable/reader.c                   | 28 +++++++++++++++---------
 reftable/reader.h                   |  6 ++---
 reftable/reftable-reader.h          |  8 +++----
 t/unit-tests/t-reftable-readwrite.c | 34 +++++++++++++++++++----------
 5 files changed, 50 insertions(+), 30 deletions(-)

diff --git a/reftable/merged.c b/reftable/merged.c
index 5a8ea8ae779..741f62ea638 100644
--- a/reftable/merged.c
+++ b/reftable/merged.c
@@ -244,7 +244,9 @@ int merged_table_init_iter(struct reftable_merged_table *mt,
 
 	for (size_t i = 0; i < mt->readers_len; i++) {
 		reftable_record_init(&subiters[i].rec, typ);
-		reader_init_iter(mt->readers[i], &subiters[i].iter, typ);
+		ret = reader_init_iter(mt->readers[i], &subiters[i].iter, typ);
+		if (ret < 0)
+			goto out;
 	}
 
 	REFTABLE_CALLOC_ARRAY(mi, 1);
diff --git a/reftable/reader.c b/reftable/reader.c
index 485ee085dac..f696e992dfc 100644
--- a/reftable/reader.c
+++ b/reftable/reader.c
@@ -554,32 +554,37 @@ static void iterator_from_table_iter(struct reftable_iterator *it,
 	it->ops = &table_iter_vtable;
 }
 
-void reader_init_iter(struct reftable_reader *r,
-		      struct reftable_iterator *it,
-		      uint8_t typ)
+int reader_init_iter(struct reftable_reader *r,
+		     struct reftable_iterator *it,
+		     uint8_t typ)
 {
 	struct reftable_reader_offsets *offs = reader_offsets_for(r, typ);
 
 	if (offs->is_present) {
 		struct table_iter *ti;
 		REFTABLE_ALLOC_ARRAY(ti, 1);
+		if (!ti)
+			return REFTABLE_OUT_OF_MEMORY_ERROR;
+
 		table_iter_init(ti, r);
 		iterator_from_table_iter(it, ti);
 	} else {
 		iterator_set_empty(it);
 	}
+
+	return 0;
 }
 
-void reftable_reader_init_ref_iterator(struct reftable_reader *r,
-				       struct reftable_iterator *it)
+int reftable_reader_init_ref_iterator(struct reftable_reader *r,
+				      struct reftable_iterator *it)
 {
-	reader_init_iter(r, it, BLOCK_TYPE_REF);
+	return reader_init_iter(r, it, BLOCK_TYPE_REF);
 }
 
-void reftable_reader_init_log_iterator(struct reftable_reader *r,
-				       struct reftable_iterator *it)
+int reftable_reader_init_log_iterator(struct reftable_reader *r,
+				      struct reftable_iterator *it)
 {
-	reader_init_iter(r, it, BLOCK_TYPE_LOG);
+	return reader_init_iter(r, it, BLOCK_TYPE_LOG);
 }
 
 int reftable_reader_new(struct reftable_reader **out,
@@ -689,7 +694,10 @@ static int reftable_reader_refs_for_indexed(struct reftable_reader *r,
 	struct indexed_table_ref_iter *itr = NULL;
 
 	/* Look through the reverse index. */
-	reader_init_iter(r, &oit, BLOCK_TYPE_OBJ);
+	err = reader_init_iter(r, &oit, BLOCK_TYPE_OBJ);
+	if (err < 0)
+		goto done;
+
 	err = iterator_seek(&oit, &want);
 	if (err != 0)
 		goto done;
diff --git a/reftable/reader.h b/reftable/reader.h
index 3710ee09b4c..02d10c5d37e 100644
--- a/reftable/reader.h
+++ b/reftable/reader.h
@@ -56,9 +56,9 @@ struct reftable_reader {
 
 const char *reader_name(struct reftable_reader *r);
 
-void reader_init_iter(struct reftable_reader *r,
-		      struct reftable_iterator *it,
-		      uint8_t typ);
+int reader_init_iter(struct reftable_reader *r,
+		     struct reftable_iterator *it,
+		     uint8_t typ);
 
 /* initialize a block reader to read from `r` */
 int reader_init_block_reader(struct reftable_reader *r, struct block_reader *br,
diff --git a/reftable/reftable-reader.h b/reftable/reftable-reader.h
index a600452b565..6a2d0b693f5 100644
--- a/reftable/reftable-reader.h
+++ b/reftable/reftable-reader.h
@@ -46,12 +46,12 @@ void reftable_reader_incref(struct reftable_reader *reader);
 void reftable_reader_decref(struct reftable_reader *reader);
 
 /* Initialize a reftable iterator for reading refs. */
-void reftable_reader_init_ref_iterator(struct reftable_reader *r,
-				       struct reftable_iterator *it);
+int reftable_reader_init_ref_iterator(struct reftable_reader *r,
+				      struct reftable_iterator *it);
 
 /* Initialize a reftable iterator for reading logs. */
-void reftable_reader_init_log_iterator(struct reftable_reader *r,
-				       struct reftable_iterator *it);
+int reftable_reader_init_log_iterator(struct reftable_reader *r,
+				      struct reftable_iterator *it);
 
 /* returns the hash ID used in this table. */
 uint32_t reftable_reader_hash_id(struct reftable_reader *r);
diff --git a/t/unit-tests/t-reftable-readwrite.c b/t/unit-tests/t-reftable-readwrite.c
index e1b235a5f13..acca927a2cf 100644
--- a/t/unit-tests/t-reftable-readwrite.c
+++ b/t/unit-tests/t-reftable-readwrite.c
@@ -206,7 +206,8 @@ static void t_log_write_read(void)
 	err = reftable_reader_new(&reader, &source, "file.log");
 	check(!err);
 
-	reftable_reader_init_ref_iterator(reader, &it);
+	err = reftable_reader_init_ref_iterator(reader, &it);
+	check(!err);
 
 	err = reftable_iterator_seek_ref(&it, names[N - 1]);
 	check(!err);
@@ -221,8 +222,8 @@ static void t_log_write_read(void)
 	reftable_iterator_destroy(&it);
 	reftable_ref_record_release(&ref);
 
-	reftable_reader_init_log_iterator(reader, &it);
-
+	err = reftable_reader_init_log_iterator(reader, &it);
+	check(!err);
 	err = reftable_iterator_seek_log(&it, "");
 	check(!err);
 
@@ -296,7 +297,8 @@ static void t_log_zlib_corruption(void)
 	err = reftable_reader_new(&reader, &source, "file.log");
 	check(!err);
 
-	reftable_reader_init_log_iterator(reader, &it);
+	err = reftable_reader_init_log_iterator(reader, &it);
+	check(!err);
 	err = reftable_iterator_seek_log(&it, "refname");
 	check_int(err, ==, REFTABLE_ZLIB_ERROR);
 
@@ -325,7 +327,8 @@ static void t_table_read_write_sequential(void)
 	err = reftable_reader_new(&reader, &source, "file.ref");
 	check(!err);
 
-	reftable_reader_init_ref_iterator(reader, &it);
+	err = reftable_reader_init_ref_iterator(reader, &it);
+	check(!err);
 	err = reftable_iterator_seek_ref(&it, "");
 	check(!err);
 
@@ -376,7 +379,8 @@ static void t_table_read_api(void)
 	err = reftable_reader_new(&reader, &source, "file.ref");
 	check(!err);
 
-	reftable_reader_init_ref_iterator(reader, &it);
+	err = reftable_reader_init_ref_iterator(reader, &it);
+	check(!err);
 	err = reftable_iterator_seek_ref(&it, names[0]);
 	check(!err);
 
@@ -419,7 +423,8 @@ static void t_table_read_write_seek(int index, int hash_id)
 	}
 
 	for (i = 1; i < N; i++) {
-		reftable_reader_init_ref_iterator(reader, &it);
+		err = reftable_reader_init_ref_iterator(reader, &it);
+		check(!err);
 		err = reftable_iterator_seek_ref(&it, names[i]);
 		check(!err);
 		err = reftable_iterator_next_ref(&it, &ref);
@@ -435,7 +440,8 @@ static void t_table_read_write_seek(int index, int hash_id)
 	strbuf_addstr(&pastLast, names[N - 1]);
 	strbuf_addstr(&pastLast, "/");
 
-	reftable_reader_init_ref_iterator(reader, &it);
+	err = reftable_reader_init_ref_iterator(reader, &it);
+	check(!err);
 	err = reftable_iterator_seek_ref(&it, pastLast.buf);
 	if (err == 0) {
 		struct reftable_ref_record ref = { 0 };
@@ -534,7 +540,8 @@ static void t_table_refs_for(int indexed)
 	if (!indexed)
 		reader->obj_offsets.is_present = 0;
 
-	reftable_reader_init_ref_iterator(reader, &it);
+	err = reftable_reader_init_ref_iterator(reader, &it);
+	check(!err);
 	err = reftable_iterator_seek_ref(&it, "");
 	check(!err);
 	reftable_iterator_destroy(&it);
@@ -593,7 +600,8 @@ static void t_write_empty_table(void)
 	err = reftable_reader_new(&rd, &source, "filename");
 	check(!err);
 
-	reftable_reader_init_ref_iterator(rd, &it);
+	err = reftable_reader_init_ref_iterator(rd, &it);
+	check(!err);
 	err = reftable_iterator_seek_ref(&it, "");
 	check(!err);
 
@@ -802,7 +810,8 @@ static void t_write_multiple_indices(void)
 	 * Seeking the log uses the log index now. In case there is any
 	 * confusion regarding indices we would notice here.
 	 */
-	reftable_reader_init_log_iterator(reader, &it);
+	err = reftable_reader_init_log_iterator(reader, &it);
+	check(!err);
 	err = reftable_iterator_seek_log(&it, "");
 	check(!err);
 
@@ -858,7 +867,8 @@ static void t_write_multi_level_index(void)
 	/*
 	 * Seeking the last ref should work as expected.
 	 */
-	reftable_reader_init_ref_iterator(reader, &it);
+	err = reftable_reader_init_ref_iterator(reader, &it);
+	check(!err);
 	err = reftable_iterator_seek_ref(&it, "refs/heads/199");
 	check(!err);
 
-- 
2.46.0.551.gc5ee8f2d1c.dirty