improve-libpq-OOM-reporting.patch

diff --git a/src/interfaces/libpq/fe-auth-scram.c b/src/interfaces/libpq/fe-auth-scram.c
index 4337e89ce9..48565343eb 100644
--- a/src/interfaces/libpq/fe-auth-scram.c
+++ b/src/interfaces/libpq/fe-auth-scram.c
@@ -378,8 +378,7 @@ build_client_first_message(fe_scram_state *state)
 	state->client_nonce = malloc(encoded_len + 1);
 	if (state->client_nonce == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return NULL;
 	}
 	encoded_len = pg_b64_encode(raw_nonce, SCRAM_RAW_NONCE_LEN,
@@ -453,8 +452,7 @@ build_client_first_message(fe_scram_state *state)
 
 oom_error:
 	termPQExpBuffer(&buf);
-	appendPQExpBufferStr(&conn->errorMessage,
-						 libpq_gettext("out of memory\n"));
+	pqReportOOM(conn);
 	return NULL;
 }
 
@@ -607,8 +605,7 @@ build_client_final_message(fe_scram_state *state)
 
 oom_error:
 	termPQExpBuffer(&buf);
-	appendPQExpBufferStr(&conn->errorMessage,
-						 libpq_gettext("out of memory\n"));
+	pqReportOOM(conn);
 	return NULL;
 }
 
@@ -628,8 +625,7 @@ read_server_first_message(fe_scram_state *state, char *input)
 	state->server_first_message = strdup(input);
 	if (state->server_first_message == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return false;
 	}
 
@@ -654,8 +650,7 @@ read_server_first_message(fe_scram_state *state, char *input)
 	state->nonce = strdup(nonce);
 	if (state->nonce == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return false;
 	}
 
@@ -669,8 +664,7 @@ read_server_first_message(fe_scram_state *state, char *input)
 	state->salt = malloc(decoded_salt_len);
 	if (state->salt == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return false;
 	}
 	state->saltlen = pg_b64_decode(encoded_salt,
@@ -719,8 +713,7 @@ read_server_final_message(fe_scram_state *state, char *input)
 	state->server_final_message = strdup(input);
 	if (!state->server_final_message)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return false;
 	}
 
@@ -758,8 +751,7 @@ read_server_final_message(fe_scram_state *state, char *input)
 	decoded_server_signature = malloc(server_signature_len);
 	if (!decoded_server_signature)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return false;
 	}
 
diff --git a/src/interfaces/libpq/fe-auth.c b/src/interfaces/libpq/fe-auth.c
index 3421ed4685..c190f5ced9 100644
--- a/src/interfaces/libpq/fe-auth.c
+++ b/src/interfaces/libpq/fe-auth.c
@@ -73,9 +73,7 @@ pg_GSS_continue(PGconn *conn, int payloadlen)
 		ginbuf.value = malloc(payloadlen);
 		if (!ginbuf.value)
 		{
-			appendPQExpBuffer(&conn->errorMessage,
-							  libpq_gettext("out of memory allocating GSSAPI buffer (%d)\n"),
-							  payloadlen);
+			pqReportOOM(conn);
 			return STATUS_ERROR;
 		}
 		if (pqGetnchar(ginbuf.value, payloadlen, conn))
@@ -227,9 +225,7 @@ pg_SSPI_continue(PGconn *conn, int payloadlen)
 		inputbuf = malloc(payloadlen);
 		if (!inputbuf)
 		{
-			appendPQExpBuffer(&conn->errorMessage,
-							  libpq_gettext("out of memory allocating SSPI buffer (%d)\n"),
-							  payloadlen);
+			pqReportOOM(conn);
 			return STATUS_ERROR;
 		}
 		if (pqGetnchar(inputbuf, payloadlen, conn))
@@ -287,8 +283,7 @@ pg_SSPI_continue(PGconn *conn, int payloadlen)
 		conn->sspictx = malloc(sizeof(CtxtHandle));
 		if (conn->sspictx == NULL)
 		{
-			appendPQExpBufferStr(&conn->errorMessage,
-								 libpq_gettext("out of memory\n"));
+			pqReportOOM(conn);
 			return STATUS_ERROR;
 		}
 		memcpy(conn->sspictx, &newContext, sizeof(CtxtHandle));
@@ -359,8 +354,7 @@ pg_SSPI_startup(PGconn *conn, int use_negotiate, int payloadlen)
 	conn->sspicred = malloc(sizeof(CredHandle));
 	if (conn->sspicred == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return STATUS_ERROR;
 	}
 
@@ -395,8 +389,7 @@ pg_SSPI_startup(PGconn *conn, int use_negotiate, int payloadlen)
 	conn->sspitarget = malloc(strlen(conn->krbsrvname) + strlen(host) + 2);
 	if (!conn->sspitarget)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return STATUS_ERROR;
 	}
 	sprintf(conn->sspitarget, "%s/%s", conn->krbsrvname, host);
@@ -620,8 +613,7 @@ oom_error:
 	termPQExpBuffer(&mechanism_buf);
 	if (initialresponse)
 		free(initialresponse);
-	appendPQExpBufferStr(&conn->errorMessage,
-						 libpq_gettext("out of memory\n"));
+	pqReportOOM(conn);
 	return STATUS_ERROR;
 }
 
@@ -644,9 +636,7 @@ pg_SASL_continue(PGconn *conn, int payloadlen, bool final)
 	challenge = malloc(payloadlen + 1);
 	if (!challenge)
 	{
-		appendPQExpBuffer(&conn->errorMessage,
-						  libpq_gettext("out of memory allocating SASL buffer (%d)\n"),
-						  payloadlen);
+		pqReportOOM(conn);
 		return STATUS_ERROR;
 	}
 
@@ -795,8 +785,7 @@ pg_password_sendauth(PGconn *conn, const char *password, AuthRequest areq)
 				crypt_pwd = malloc(2 * (MD5_PASSWD_LEN + 1));
 				if (!crypt_pwd)
 				{
-					appendPQExpBufferStr(&conn->errorMessage,
-										 libpq_gettext("out of memory\n"));
+					pqReportOOM(conn);
 					return STATUS_ERROR;
 				}
 
@@ -1153,8 +1142,7 @@ pg_fe_getauthname(PQExpBuffer errorMessage)
 	{
 		result = strdup(name);
 		if (result == NULL && errorMessage)
-			appendPQExpBufferStr(errorMessage,
-								 libpq_gettext("out of memory\n"));
+			pqReportOOMBuffer(errorMessage);
 	}
 
 	pgunlock_thread();
@@ -1303,8 +1291,7 @@ PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user,
 	}
 
 	if (!crypt_pwd)
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 
 	return crypt_pwd;
 }
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index e950b41374..071e87b71f 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -903,8 +903,7 @@ fillPGconn(PGconn *conn, PQconninfoOption *connOptions)
 				*connmember = strdup(tmp);
 				if (*connmember == NULL)
 				{
-					appendPQExpBufferStr(&conn->errorMessage,
-										 libpq_gettext("out of memory\n"));
+					pqReportOOM(conn);
 					return false;
 				}
 			}
@@ -1447,8 +1446,7 @@ connectOptions2(PGconn *conn)
 
 oom_error:
 	conn->status = CONNECTION_BAD;
-	appendPQExpBufferStr(&conn->errorMessage,
-						 libpq_gettext("out of memory\n"));
+	pqReportOOM(conn);
 	return false;
 }
 
@@ -1616,8 +1614,7 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 
 oom_error:
 	conn->status = CONNECTION_BAD;
-	appendPQExpBufferStr(&conn->errorMessage,
-						 libpq_gettext("out of memory\n"));
+	pqReportOOM(conn);
 	return conn;
 }
 
@@ -2968,8 +2965,7 @@ keep_going:						/* We will come back to here until there is
 													EnvironmentOptions);
 				if (!startpacket)
 				{
-					appendPQExpBufferStr(&conn->errorMessage,
-										 libpq_gettext("out of memory\n"));
+					pqReportOOM(conn);
 					goto error_return;
 				}
 
@@ -4650,7 +4646,7 @@ ldapServiceLookup(const char *purl, PQconninfoOption *options,
 
 	if ((url = strdup(purl)) == NULL)
 	{
-		appendPQExpBufferStr(errorMessage, libpq_gettext("out of memory\n"));
+		pqReportOOMBuffer(errorMessage);
 		return 3;
 	}
 
@@ -4910,8 +4906,7 @@ ldapServiceLookup(const char *purl, PQconninfoOption *options,
 		size += values[i]->bv_len + 1;
 	if ((result = malloc(size)) == NULL)
 	{
-		appendPQExpBufferStr(errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOMBuffer(errorMessage);
 		ldap_value_free_len(values);
 		ldap_unbind(ld);
 		return 3;
@@ -5029,8 +5024,7 @@ ldapServiceLookup(const char *purl, PQconninfoOption *options,
 						options[i].val = strdup(optval);
 						if (!options[i].val)
 						{
-							appendPQExpBufferStr(errorMessage,
-												 libpq_gettext("out of memory\n"));
+							pqReportOOMBuffer(errorMessage);
 							free(result);
 							return 3;
 						}
@@ -5281,8 +5275,7 @@ parseServiceFile(const char *serviceFile,
 							options[i].val = strdup(val);
 						if (!options[i].val)
 						{
-							appendPQExpBufferStr(errorMessage,
-												 libpq_gettext("out of memory\n"));
+							pqReportOOMBuffer(errorMessage);
 							result = 3;
 							goto exit;
 						}
@@ -5362,8 +5355,7 @@ conninfo_init(PQExpBuffer errorMessage)
 	options = (PQconninfoOption *) malloc(sizeof(PQconninfoOption) * sizeof(PQconninfoOptions) / sizeof(PQconninfoOptions[0]));
 	if (options == NULL)
 	{
-		appendPQExpBufferStr(errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOMBuffer(errorMessage);
 		return NULL;
 	}
 	opt_dest = options;
@@ -5461,8 +5453,7 @@ conninfo_parse(const char *conninfo, PQExpBuffer errorMessage,
 	/* Need a modifiable copy of the input string */
 	if ((buf = strdup(conninfo)) == NULL)
 	{
-		appendPQExpBufferStr(errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOMBuffer(errorMessage);
 		PQconninfoFree(options);
 		return NULL;
 	}
@@ -5717,8 +5708,7 @@ conninfo_array_parse(const char *const *keywords, const char *const *values,
 								options[k].val = strdup(str_option->val);
 								if (!options[k].val)
 								{
-									appendPQExpBufferStr(errorMessage,
-														 libpq_gettext("out of memory\n"));
+									pqReportOOMBuffer(errorMessage);
 									PQconninfoFree(options);
 									PQconninfoFree(dbname_options);
 									return NULL;
@@ -5746,8 +5736,7 @@ conninfo_array_parse(const char *const *keywords, const char *const *values,
 				option->val = strdup(pvalue);
 				if (!option->val)
 				{
-					appendPQExpBufferStr(errorMessage,
-										 libpq_gettext("out of memory\n"));
+					pqReportOOMBuffer(errorMessage);
 					PQconninfoFree(options);
 					PQconninfoFree(dbname_options);
 					return NULL;
@@ -5818,8 +5807,7 @@ conninfo_add_defaults(PQconninfoOption *options, PQExpBuffer errorMessage)
 				if (!option->val)
 				{
 					if (errorMessage)
-						appendPQExpBufferStr(errorMessage,
-											 libpq_gettext("out of memory\n"));
+						pqReportOOMBuffer(errorMessage);
 					return false;
 				}
 				continue;
@@ -5842,8 +5830,7 @@ conninfo_add_defaults(PQconninfoOption *options, PQExpBuffer errorMessage)
 				if (!option->val)
 				{
 					if (errorMessage)
-						appendPQExpBufferStr(errorMessage,
-											 libpq_gettext("out of memory\n"));
+						pqReportOOMBuffer(errorMessage);
 					return false;
 				}
 				continue;
@@ -5860,8 +5847,7 @@ conninfo_add_defaults(PQconninfoOption *options, PQExpBuffer errorMessage)
 			if (!option->val)
 			{
 				if (errorMessage)
-					appendPQExpBufferStr(errorMessage,
-										 libpq_gettext("out of memory\n"));
+					pqReportOOMBuffer(errorMessage);
 				return false;
 			}
 			continue;
@@ -5961,8 +5947,7 @@ conninfo_uri_parse_options(PQconninfoOption *options, const char *uri,
 	initPQExpBuffer(&portbuf);
 	if (PQExpBufferDataBroken(hostbuf) || PQExpBufferDataBroken(portbuf))
 	{
-		appendPQExpBufferStr(errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOMBuffer(errorMessage);
 		goto cleanup;
 	}
 
@@ -5970,8 +5955,7 @@ conninfo_uri_parse_options(PQconninfoOption *options, const char *uri,
 	buf = strdup(uri);
 	if (buf == NULL)
 	{
-		appendPQExpBufferStr(errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOMBuffer(errorMessage);
 		goto cleanup;
 	}
 	start = buf;
@@ -6329,7 +6313,7 @@ conninfo_uri_decode(const char *str, PQExpBuffer errorMessage)
 	buf = malloc(strlen(str) + 1);
 	if (buf == NULL)
 	{
-		appendPQExpBufferStr(errorMessage, libpq_gettext("out of memory\n"));
+		pqReportOOMBuffer(errorMessage);
 		return NULL;
 	}
 	p = buf;
@@ -6479,7 +6463,7 @@ conninfo_storeval(PQconninfoOption *connOptions,
 		value_copy = strdup(value);
 		if (value_copy == NULL)
 		{
-			appendPQExpBufferStr(errorMessage, libpq_gettext("out of memory\n"));
+			pqReportOOMBuffer(errorMessage);
 			return NULL;
 		}
 	}
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index aca81890bb..dc00448292 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -1205,8 +1205,7 @@ pqAllocCmdQueueEntry(PGconn *conn)
 		entry = (PGcmdQueueEntry *) malloc(sizeof(PGcmdQueueEntry));
 		if (entry == NULL)
 		{
-			appendPQExpBufferStr(&conn->errorMessage,
-								 libpq_gettext("out of memory\n"));
+			pqReportOOM(conn);
 			return NULL;
 		}
 	}
@@ -3025,8 +3024,7 @@ pqPipelineProcessQueue(PGconn *conn)
 		conn->result = PQmakeEmptyPGresult(conn, PGRES_PIPELINE_ABORTED);
 		if (!conn->result)
 		{
-			appendPQExpBufferStr(&conn->errorMessage,
-								 libpq_gettext("out of memory\n"));
+			pqReportOOM(conn);
 			pqSaveErrorResult(conn);
 			return;
 		}
@@ -3981,8 +3979,7 @@ PQescapeInternal(PGconn *conn, const char *str, size_t len, bool as_ident)
 	result = rp = (char *) malloc(result_size);
 	if (rp == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return NULL;
 	}
 
@@ -4146,8 +4143,7 @@ PQescapeByteaInternal(PGconn *conn,
 	if (rp == NULL)
 	{
 		if (conn)
-			appendPQExpBufferStr(&conn->errorMessage,
-								 libpq_gettext("out of memory\n"));
+			pqReportOOM(conn);
 		return NULL;
 	}
 
diff --git a/src/interfaces/libpq/fe-gssapi-common.c b/src/interfaces/libpq/fe-gssapi-common.c
index 9e8aeae119..cd5a0b6c70 100644
--- a/src/interfaces/libpq/fe-gssapi-common.c
+++ b/src/interfaces/libpq/fe-gssapi-common.c
@@ -107,8 +107,7 @@ pg_GSS_load_servicename(PGconn *conn)
 	temp_gbuf.value = (char *) malloc(maxlen);
 	if (!temp_gbuf.value)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return STATUS_ERROR;
 	}
 	snprintf(temp_gbuf.value, maxlen, "%s@%s",
diff --git a/src/interfaces/libpq/fe-lobj.c b/src/interfaces/libpq/fe-lobj.c
index ffd9926dc4..29ce74af8f 100644
--- a/src/interfaces/libpq/fe-lobj.c
+++ b/src/interfaces/libpq/fe-lobj.c
@@ -877,8 +877,7 @@ lo_initialize(PGconn *conn)
 	lobjfuncs = (PGlobjfuncs *) malloc(sizeof(PGlobjfuncs));
 	if (lobjfuncs == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return -1;
 	}
 	MemSet((char *) lobjfuncs, 0, sizeof(PGlobjfuncs));
diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index 9a2a970293..92590a9d80 100644
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -339,8 +339,7 @@ pqCheckOutBufferSpace(size_t bytes_needed, PGconn *conn)
 	}
 
 	/* realloc failed. Probably out of memory */
-	appendPQExpBufferStr(&conn->errorMessage,
-						 "cannot allocate memory for output buffer\n");
+	pqReportOOM(conn);
 	return EOF;
 }
 
@@ -433,8 +432,7 @@ pqCheckInBufferSpace(size_t bytes_needed, PGconn *conn)
 	}
 
 	/* realloc failed. Probably out of memory */
-	appendPQExpBufferStr(&conn->errorMessage,
-						 "cannot allocate memory for input buffer\n");
+	pqReportOOM(conn);
 	return EOF;
 }
 
@@ -1233,6 +1231,45 @@ PQenv2encoding(void)
 	return encoding;
 }
 
+/*
+ * Report an out-of-memory error by appending a message to conn->errorMessage.
+ *
+ * This task is just common enough, and nontrivial enough, to deserve its own
+ * subroutine.
+ */
+void
+pqReportOOM(PGconn *conn)
+{
+	pqReportOOMBuffer(&conn->errorMessage);
+}
+
+/*
+ * As above, but work with a bare error-message-buffer pointer.
+ */
+void
+pqReportOOMBuffer(PQExpBuffer errorMessage)
+{
+	const char *msg = libpq_gettext("out of memory\n");
+
+	/*
+	 * First just try to append the message.  Even though we're up against
+	 * OOM, this is likely to succeed because of unused space within
+	 * errorMessage's buffer.
+	 */
+	appendPQExpBufferStr(errorMessage, msg);
+
+	/*
+	 * If that didn't succeed, it'll have marked the buffer broken.  Our
+	 * fallback plan is to reset the buffer (hopefully regaining some space)
+	 * and try again.  If still no luck, not much we can do.
+	 */
+	if (PQExpBufferBroken(errorMessage))
+	{
+		resetPQExpBuffer(errorMessage);
+		appendPQExpBufferStr(errorMessage, msg);
+	}
+}
+
 
 #ifdef ENABLE_NLS
 
diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 2e83305348..08b9b5d97e 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -215,8 +215,7 @@ pqParseInput3(PGconn *conn)
 														   PGRES_COMMAND_OK);
 						if (!conn->result)
 						{
-							appendPQExpBufferStr(&conn->errorMessage,
-												 libpq_gettext("out of memory"));
+							pqReportOOM(conn);
 							pqSaveErrorResult(conn);
 						}
 					}
@@ -240,8 +239,7 @@ pqParseInput3(PGconn *conn)
 														   PGRES_PIPELINE_SYNC);
 						if (!conn->result)
 						{
-							appendPQExpBufferStr(&conn->errorMessage,
-												 libpq_gettext("out of memory"));
+							pqReportOOM(conn);
 							pqSaveErrorResult(conn);
 						}
 						else
@@ -269,8 +267,7 @@ pqParseInput3(PGconn *conn)
 														   PGRES_EMPTY_QUERY);
 						if (!conn->result)
 						{
-							appendPQExpBufferStr(&conn->errorMessage,
-												 libpq_gettext("out of memory"));
+							pqReportOOM(conn);
 							pqSaveErrorResult(conn);
 						}
 					}
@@ -287,8 +284,7 @@ pqParseInput3(PGconn *conn)
 															   PGRES_COMMAND_OK);
 							if (!conn->result)
 							{
-								appendPQExpBufferStr(&conn->errorMessage,
-													 libpq_gettext("out of memory"));
+								pqReportOOM(conn);
 								pqSaveErrorResult(conn);
 							}
 						}
@@ -367,8 +363,7 @@ pqParseInput3(PGconn *conn)
 															   PGRES_COMMAND_OK);
 							if (!conn->result)
 							{
-								appendPQExpBufferStr(&conn->errorMessage,
-													 libpq_gettext("out of memory"));
+								pqReportOOM(conn);
 								pqSaveErrorResult(conn);
 							}
 						}
@@ -650,10 +645,10 @@ advance_and_error:
 	 * freeing the old result first greatly improves the odds that gettext()
 	 * will succeed in providing a translation.
 	 */
-	if (!errmsg)
-		errmsg = libpq_gettext("out of memory for query result");
-
-	appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
+	if (errmsg)
+		appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
+	else
+		pqReportOOM(conn);
 	pqSaveErrorResult(conn);
 
 	/*
@@ -739,9 +734,10 @@ advance_and_error:
 	 * freeing the old result first greatly improves the odds that gettext()
 	 * will succeed in providing a translation.
 	 */
-	if (!errmsg)
-		errmsg = libpq_gettext("out of memory");
-	appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
+	if (errmsg)
+		appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
+	else
+		pqReportOOM(conn);
 	pqSaveErrorResult(conn);
 
 	/*
@@ -856,10 +852,10 @@ advance_and_error:
 	 * freeing the old result first greatly improves the odds that gettext()
 	 * will succeed in providing a translation.
 	 */
-	if (!errmsg)
-		errmsg = libpq_gettext("out of memory for query result");
-
-	appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
+	if (errmsg)
+		appendPQExpBuffer(&conn->errorMessage, "%s\n", errmsg);
+	else
+		pqReportOOM(conn);
 	pqSaveErrorResult(conn);
 
 	/*
@@ -971,8 +967,7 @@ pqGetErrorNotice3(PGconn *conn, bool isError)
 		pqClearAsyncResult(conn);	/* redundant, but be safe */
 		conn->result = res;
 		if (PQExpBufferDataBroken(workBuf))
-			appendPQExpBufferStr(&conn->errorMessage,
-								 libpq_gettext("out of memory"));
+			pqReportOOM(conn);
 		else
 			appendPQExpBufferStr(&conn->errorMessage, workBuf.data);
 	}
@@ -1013,7 +1008,7 @@ pqBuildErrorMessage3(PQExpBuffer msg, const PGresult *res,
 	/* If we couldn't allocate a PGresult, just say "out of memory" */
 	if (res == NULL)
 	{
-		appendPQExpBufferStr(msg, libpq_gettext("out of memory\n"));
+		pqReportOOMBuffer(msg);
 		return;
 	}
 
@@ -1720,8 +1715,7 @@ pqGetCopyData3(PGconn *conn, char **buffer, int async)
 			*buffer = (char *) malloc(msgLength + 1);
 			if (*buffer == NULL)
 			{
-				appendPQExpBufferStr(&conn->errorMessage,
-									 libpq_gettext("out of memory\n"));
+				pqReportOOM(conn);
 				return -2;
 			}
 			memcpy(*buffer, &conn->inBuffer[conn->inCursor], msgLength);
diff --git a/src/interfaces/libpq/fe-secure-common.c b/src/interfaces/libpq/fe-secure-common.c
index afa5d133e1..67e10d8200 100644
--- a/src/interfaces/libpq/fe-secure-common.c
+++ b/src/interfaces/libpq/fe-secure-common.c
@@ -106,8 +106,7 @@ pq_verify_peer_name_matches_certificate_name(PGconn *conn,
 	name = malloc(namelen + 1);
 	if (name == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return -1;
 	}
 	memcpy(name, namedata, namelen);
diff --git a/src/interfaces/libpq/fe-secure-gssapi.c b/src/interfaces/libpq/fe-secure-gssapi.c
index c783a53734..d28cd6bdd7 100644
--- a/src/interfaces/libpq/fe-secure-gssapi.c
+++ b/src/interfaces/libpq/fe-secure-gssapi.c
@@ -500,8 +500,7 @@ pqsecure_open_gss(PGconn *conn)
 		PqGSSResultBuffer = malloc(PQ_GSS_RECV_BUFFER_SIZE);
 		if (!PqGSSSendBuffer || !PqGSSRecvBuffer || !PqGSSResultBuffer)
 		{
-			appendPQExpBufferStr(&conn->errorMessage,
-								 libpq_gettext("out of memory\n"));
+			pqReportOOM(conn);
 			return PGRES_POLLING_FAILED;
 		}
 		PqGSSSendLength = PqGSSSendNext = PqGSSSendConsumed = 0;
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 2ee5a0a40a..d530ea9939 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -436,8 +436,7 @@ pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len)
 	cert_hash = malloc(hash_size);
 	if (cert_hash == NULL)
 	{
-		appendPQExpBufferStr(&conn->errorMessage,
-							 libpq_gettext("out of memory\n"));
+		pqReportOOM(conn);
 		return NULL;
 	}
 	memcpy(cert_hash, hash, hash_size);
@@ -1134,8 +1133,7 @@ initialize_SSL(PGconn *conn)
 
 			if (engine_str == NULL)
 			{
-				appendPQExpBufferStr(&conn->errorMessage,
-									 libpq_gettext("out of memory\n"));
+				pqReportOOM(conn);
 				return -1;
 			}
 
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index e9f214b61b..3e7bf57b5f 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -697,6 +697,8 @@ extern int	pqWaitTimed(int forRead, int forWrite, PGconn *conn,
 						time_t finish_time);
 extern int	pqReadReady(PGconn *conn);
 extern int	pqWriteReady(PGconn *conn);
+extern void pqReportOOM(PGconn *conn);
+extern void pqReportOOMBuffer(PQExpBuffer errorMessage);
 
 /* === in fe-secure.c === */