From 98686e1ea142d88cc29eaea012047bb73f1ae5cd Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 15 Mar 2009 22:05:44 +0000
Subject: [PATCH] Fix contrib/hstore to throw an error for keys or values that
 don't fit in its data structure, rather than silently truncating them. 
 Andrew Gierth

---
 contrib/hstore/README.hstore |  4 ++++
 contrib/hstore/hstore.h      |  8 ++++++++
 contrib/hstore/hstore_io.c   | 25 +++++++++++++++++++++++--
 contrib/hstore/hstore_op.c   |  4 ++--
 4 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/contrib/hstore/README.hstore b/contrib/hstore/README.hstore
index 5fdceb1b98..d1b9d44d1c 100644
--- a/contrib/hstore/README.hstore
+++ b/contrib/hstore/README.hstore
@@ -184,3 +184,7 @@ select key, count(*) from (select (each(h)).key from testhstore) as stat group b
  title     |   190
  org       |   189
 ...................
+
+In the current implementation, neither the key nor the value
+string can exceed 65535 bytes in length; an error will be thrown if this
+limit is exceeded. These maximum lengths may change in future releases.
diff --git a/contrib/hstore/hstore.h b/contrib/hstore/hstore.h
index 20ae203416..776dc88892 100644
--- a/contrib/hstore/hstore.h
+++ b/contrib/hstore/hstore.h
@@ -20,6 +20,11 @@ typedef struct
 				pos:31;
 }	HEntry;
 
+/* these are determined by the sizes of the keylen and vallen fields */
+/* in struct HEntry and struct Pairs */
+#define HSTORE_MAX_KEY_LEN 65535
+#define HSTORE_MAX_VALUE_LEN 65535
+
 
 typedef struct
 {
@@ -49,4 +54,7 @@ typedef struct
 int			comparePairs(const void *a, const void *b);
 int			uniquePairs(Pairs * a, int4 l, int4 *buflen);
 
+size_t      hstoreCheckKeyLen(size_t len);
+size_t      hstoreCheckValLen(size_t len);
+
 #endif
diff --git a/contrib/hstore/hstore_io.c b/contrib/hstore/hstore_io.c
index e01cb4e759..08fc32e509 100644
--- a/contrib/hstore/hstore_io.c
+++ b/contrib/hstore/hstore_io.c
@@ -182,7 +182,7 @@ parse_hstore(HSParser * state)
 				state->pairs = (Pairs *) repalloc(state->pairs, sizeof(Pairs) * state->plen);
 			}
 			state->pairs[state->pcur].key = state->word;
-			state->pairs[state->pcur].keylen = state->cur - state->word;
+			state->pairs[state->pcur].keylen = hstoreCheckKeyLen(state->cur - state->word);
 			state->pairs[state->pcur].val = NULL;
 			state->word = NULL;
 			st = WEQ;
@@ -222,7 +222,7 @@ parse_hstore(HSParser * state)
 			if (!get_val(state, true, &escaped))
 				elog(ERROR, "Unexpected end of string");
 			state->pairs[state->pcur].val = state->word;
-			state->pairs[state->pcur].vallen = state->cur - state->word;
+			state->pairs[state->pcur].vallen = hstoreCheckValLen(state->cur - state->word);
 			state->pairs[state->pcur].isnull = false;
 			state->pairs[state->pcur].needfree = true;
 			if (state->cur - state->word == 4 && !escaped)
@@ -341,6 +341,27 @@ freeHSParse(HSParser * state)
 	pfree(state->pairs);
 }
 
+size_t
+hstoreCheckKeyLen(size_t len)
+{
+	if (len > HSTORE_MAX_KEY_LEN)
+		ereport(ERROR,
+				(errcode(ERRCODE_STRING_DATA_RIGHT_TRUNCATION),
+				 errmsg("string too long for hstore key")));
+	return len;
+}
+
+size_t
+hstoreCheckValLen(size_t len)
+{
+	if (len > HSTORE_MAX_VALUE_LEN)
+		ereport(ERROR,
+				(errcode(ERRCODE_STRING_DATA_RIGHT_TRUNCATION),
+				 errmsg("string too long for hstore value")));
+	return len;
+}
+
+
 PG_FUNCTION_INFO_V1(hstore_in);
 Datum		hstore_in(PG_FUNCTION_ARGS);
 Datum
diff --git a/contrib/hstore/hstore_op.c b/contrib/hstore/hstore_op.c
index 971e93cf31..03c7c67e0d 100644
--- a/contrib/hstore/hstore_op.c
+++ b/contrib/hstore/hstore_op.c
@@ -280,8 +280,8 @@ tconvert(PG_FUNCTION_ARGS)
 	out->len = len;
 	out->size = 1;
 
-	ARRPTR(out)->keylen = VARSIZE(key) - VARHDRSZ;
-	ARRPTR(out)->vallen = VARSIZE(val) - VARHDRSZ;
+	ARRPTR(out)->keylen = hstoreCheckKeyLen(VARSIZE(key) - VARHDRSZ);
+	ARRPTR(out)->vallen = hstoreCheckValLen(VARSIZE(val) - VARHDRSZ);
 	ARRPTR(out)->valisnull = false;
 	ARRPTR(out)->pos = 0;