From 76df13f99a2324ed58a4b77cec646259a180fd72 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Tue, 15 Jan 2019 11:37:36 -0500
Subject: [PATCH 1/2] compare prepared statement text with previous to prevent
 incorrect queries - fixes #1813

---
 lib/client.js                                       |  2 +-
 lib/native/query.js                                 |  6 +++++-
 lib/query.js                                        |  4 ++++
 test/integration/client/prepared-statement-tests.js | 11 +++++++++++
 4 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/lib/client.js b/lib/client.js
index 8e7d307f7..194bc097a 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -276,7 +276,7 @@ Client.prototype._attachListeners = function (con) {
   // it again on the same client
   con.on('parseComplete', function (msg) {
     if (self.activeQuery.name) {
-      con.parsedStatements[self.activeQuery.name] = true
+      con.parsedStatements[self.activeQuery.name] = self.activeQuery.text
     }
   })
 
diff --git a/lib/native/query.js b/lib/native/query.js
index 7602d161b..27607fa4e 100644
--- a/lib/native/query.js
+++ b/lib/native/query.js
@@ -139,12 +139,16 @@ NativeQuery.prototype.submit = function (client) {
     // check if the client has already executed this named query
     // if so...just execute it again - skip the planning phase
     if (client.namedQueries[this.name]) {
+      if (this.text && client.namedQueries[this.name] !== this.text) {
+        const err = new Error(`Prepared statements must be unique — '${this.name}' was used for different queries`)
+        return after(err)
+      }
       return client.native.execute(this.name, values, after)
     }
     // plan the named query the first time, then execute it
     return client.native.prepare(this.name, this.text, values.length, function (err) {
       if (err) return after(err)
-      client.namedQueries[self.name] = true
+      client.namedQueries[self.name] = self.text
       return self.native.execute(self.name, values, after)
     })
   } else if (this.values) {
diff --git a/lib/query.js b/lib/query.js
index 94c2bc3c1..2ca462040 100644
--- a/lib/query.js
+++ b/lib/query.js
@@ -148,6 +148,10 @@ Query.prototype.submit = function (connection) {
   if (typeof this.text !== 'string' && typeof this.name !== 'string') {
     return new Error('A query must have either text or a name. Supplying neither is unsupported.')
   }
+  const previous = connection.parsedStatements[this.name]
+  if (this.text && previous && this.text !== previous) {
+    return new Error(`Prepared statements must be unique — '${this.name}' was used for different queries`)
+  }
   if (this.values && !Array.isArray(this.values)) {
     return new Error('Query values must be an array')
   }
diff --git a/test/integration/client/prepared-statement-tests.js b/test/integration/client/prepared-statement-tests.js
index 188bf8266..81048d16f 100644
--- a/test/integration/client/prepared-statement-tests.js
+++ b/test/integration/client/prepared-statement-tests.js
@@ -56,6 +56,17 @@ var suite = new helper.Suite()
 
     q.on('end', () => done())
   })
+
+  suite.test('with same name, but with different text', function (done) {
+    client.query(new Query({
+      text: 'select name from person where age >= $1 and name LIKE $2',
+      name: queryName,
+      values: [30, '%n%']
+    }), assert.calls(err => {
+      assert.equal(err.message, `Prepared statements must be unique — '${queryName}' was used for different queries`)
+      done()
+    }))
+  })
 })()
 
 ;(function () {

From 248f7a036dbdb1c15179ccc52e119f3b4e0b5c29 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Tue, 15 Jan 2019 12:52:01 -0500
Subject: [PATCH 2/2] make suggested changes to error message

---
 lib/native/query.js                                 | 2 +-
 lib/query.js                                        | 2 +-
 test/integration/client/prepared-statement-tests.js | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/native/query.js b/lib/native/query.js
index 27607fa4e..db4eb8cca 100644
--- a/lib/native/query.js
+++ b/lib/native/query.js
@@ -140,7 +140,7 @@ NativeQuery.prototype.submit = function (client) {
     // if so...just execute it again - skip the planning phase
     if (client.namedQueries[this.name]) {
       if (this.text && client.namedQueries[this.name] !== this.text) {
-        const err = new Error(`Prepared statements must be unique — '${this.name}' was used for different queries`)
+        const err = new Error(`Prepared statements must be unique - '${this.name}' was used for a different statement`)
         return after(err)
       }
       return client.native.execute(this.name, values, after)
diff --git a/lib/query.js b/lib/query.js
index 2ca462040..9e34b0d2b 100644
--- a/lib/query.js
+++ b/lib/query.js
@@ -150,7 +150,7 @@ Query.prototype.submit = function (connection) {
   }
   const previous = connection.parsedStatements[this.name]
   if (this.text && previous && this.text !== previous) {
-    return new Error(`Prepared statements must be unique — '${this.name}' was used for different queries`)
+    return new Error(`Prepared statements must be unique - '${this.name}' was used for a different statement`)
   }
   if (this.values && !Array.isArray(this.values)) {
     return new Error('Query values must be an array')
diff --git a/test/integration/client/prepared-statement-tests.js b/test/integration/client/prepared-statement-tests.js
index 81048d16f..76654eaa3 100644
--- a/test/integration/client/prepared-statement-tests.js
+++ b/test/integration/client/prepared-statement-tests.js
@@ -63,7 +63,7 @@ var suite = new helper.Suite()
       name: queryName,
       values: [30, '%n%']
     }), assert.calls(err => {
-      assert.equal(err.message, `Prepared statements must be unique — '${queryName}' was used for different queries`)
+      assert.equal(err.message, `Prepared statements must be unique - '${queryName}' was used for a different statement`)
       done()
     }))
   })