# HG changeset patch
# User jbe
# Date 1452117579 -3600
# Node ID 0e641ac7664754a8d99e436d72945376933ce1f2
# Parent  36f0d1d5ed7dc68f113fb323491ba7506ad75d05
Some code-cleanup and fixed comments; Better behavior on out-of-memory errors in certain cases

diff -r 36f0d1d5ed7d -r 0e641ac76647 libraries/mondelefant/mondelefant_native.c
--- a/libraries/mondelefant/mondelefant_native.c	Wed Jan 06 18:59:58 2016 +0100
+++ b/libraries/mondelefant/mondelefant_native.c	Wed Jan 06 22:59:39 2016 +0100
@@ -255,11 +255,11 @@
   if (!conn->pgconn) {
     lua_gc(L, LUA_GCCOLLECT, 0);
     conn->pgconn = PQconnectdb(conninfo);
+    // throw error in case of (unexpected) error of PQconnectdb call:
+    if (!conn->pgconn) return luaL_error(L,
+      "Error in libpq while creating 'PGconn' structure."
+    );
   }
-  // throw error in case of (unexpected) error of PQconnectdb call:
-  if (!conn->pgconn) return luaL_error(L,
-    "Error in libpq while creating 'PGconn' structure."
-  );
   // set metatable for userdata (ensure PQfinish on unexpected error below):
   luaL_setmetatable(L, MONDELEFANT_CONN_MT_REGKEY);
   // check result of PQconnectdb call:
@@ -559,9 +559,10 @@
   mondelefant_conn_t *conn;
   const char *input;
   size_t input_len;
+  luaL_Buffer buf;
   char *output;
   size_t output_len;
-  // get 'conn' attribute of C-struct of database connection:
+  // get database connection object:
   conn = mondelefant_get_conn(L, 1);
   // get second argument, which must be a string:
   input = luaL_checklstring(L, 2, &input_len);
@@ -570,10 +571,7 @@
     return luaL_error(L, "String to be escaped is too long.");
   }
   // allocate memory for quoted string:
-  output = malloc((2 * input_len + 3) * sizeof(char));
-  if (!output) {
-    return luaL_error(L, "Could not allocate memory for string quoting.");
-  }
+  output = luaL_buffinitsize(L, &buf, (2 * input_len + 3) * sizeof(char));
   // do escaping by calling PQescapeStringConn and enclosing result with
   // single quotes:
   output[0] = '\'';
@@ -583,9 +581,7 @@
   output[output_len + 1] = '\'';
   output[output_len + 2] = 0;
   // create Lua string:
-  lua_pushlstring(L, output, output_len + 2);
-  // free allocated memory:
-  free(output);
+  luaL_addsize(&buf, output_len + 2);
   // return Lua string:
   return 1;
 }
@@ -598,7 +594,7 @@
   char *output;
   size_t output_len;
   luaL_Buffer buf;
-  // get 'conn' attribute of C-struct of database connection:
+  // get database connection object:
   conn = mondelefant_get_conn(L, 1);
   // get second argument, which must be a string:
   input = luaL_checklstring(L, 2, &input_len);
@@ -629,7 +625,7 @@
   const char *template;
   size_t template_pos = 0;
   luaL_Buffer buf;
-  // get 'conn' attribute of C-struct of database connection:
+  // get database connection object:
   conn = mondelefant_get_conn(L, 1);
   // if second argument is a string, return this string:
   if (lua_type(L, 2) == LUA_TSTRING) {
@@ -847,7 +843,7 @@
   int sent_success;
   PGresult *res;
   int rows, cols, row, col;
-  // get 'conn' attribute of C-struct of database connection:
+  // get database connection object:
   conn = mondelefant_get_conn(L, 1);
   // calculate number of commands (2 arguments for one command):
   command_count = lua_gettop(L) / 2;