diff --git a/src/interfaces/ecpg/compatlib/informix.c b/src/interfaces/ecpg/compatlib/informix.c
index d6de3ea..8d81c83 100644
--- a/src/interfaces/ecpg/compatlib/informix.c
+++ b/src/interfaces/ecpg/compatlib/informix.c
@@ -666,12 +666,16 @@ dttofmtasc(timestamp * ts, char *output, int str_len, char *fmtstr)
 int
 intoasc(interval * i, char *str)
 {
+	char *tmp;
+
 	errno = 0;
-	str = PGTYPESinterval_to_asc(i);
+	tmp = PGTYPESinterval_to_asc(i);
 
-	if (!str)
+	if (!tmp)
 		return -errno;
 
+	memcpy(str, tmp, strlen(tmp));
+	free(tmp);
 	return 0;
 }
 
diff --git a/src/interfaces/ecpg/ecpglib/connect.c b/src/interfaces/ecpg/ecpglib/connect.c
index 55c5680..12f445d 100644
--- a/src/interfaces/ecpg/ecpglib/connect.c
+++ b/src/interfaces/ecpg/ecpglib/connect.c
@@ -298,7 +298,8 @@ ECPGconnect(int lineno, int c, const char *name, const char *user, const char *p
 		envname = getenv("PG_DBPATH");
 		if (envname)
 		{
-			ecpg_free(dbname);
+			if (dbname)
+				ecpg_free(dbname);
 			dbname = ecpg_strdup(envname, lineno);
 		}
 
@@ -314,14 +315,19 @@ ECPGconnect(int lineno, int c, const char *name, const char *user, const char *p
 	/* check if the identifier is unique */
 	if (ecpg_get_connection(connection_name))
 	{
-		ecpg_free(dbname);
+		if (dbname)
+			ecpg_free(dbname);
 		ecpg_log("ECPGconnect: connection identifier %s is already in use\n",
 				 connection_name);
 		return false;
 	}
 
 	if ((this = (struct connection *) ecpg_alloc(sizeof(struct connection), lineno)) == NULL)
+	{
+		if (dbname)
+			ecpg_free(dbname);
 		return false;
+	}
 
 	if (dbname != NULL)
 	{
diff --git a/src/interfaces/ecpg/preproc/descriptor.c b/src/interfaces/ecpg/preproc/descriptor.c
index 053a7af..ebd95d3 100644
--- a/src/interfaces/ecpg/preproc/descriptor.c
+++ b/src/interfaces/ecpg/preproc/descriptor.c
@@ -175,6 +175,7 @@ output_get_descr(char *desc_name, char *index)
 	for (results = assignments; results != NULL; results = results->next)
 	{
 		const struct variable *v = find_variable(results->variable);
+		char *str_zero = mm_strdup("0");
 
 		switch (results->value)
 		{
@@ -188,7 +189,8 @@ output_get_descr(char *desc_name, char *index)
 				break;
 		}
 		fprintf(yyout, "%s,", get_dtype(results->value));
-		ECPGdump_a_type(yyout, v->name, v->type, v->brace_level, NULL, NULL, -1, NULL, NULL, mm_strdup("0"), NULL, NULL);
+		ECPGdump_a_type(yyout, v->name, v->type, v->brace_level, NULL, NULL, -1, NULL, NULL, str_zero, NULL, NULL);
+		free(str_zero);
 	}
 	drop_assignments();
 	fputs("ECPGd_EODT);\n", yyout);
@@ -292,8 +294,12 @@ output_set_descr(char *desc_name, char *index)
 			case ECPGd_indicator:
 			case ECPGd_length:
 			case ECPGd_type:
-				fprintf(yyout, "%s,", get_dtype(results->value));
-				ECPGdump_a_type(yyout, v->name, v->type, v->brace_level, NULL, NULL, -1, NULL, NULL, mm_strdup("0"), NULL, NULL);
+				{
+					char *str_zero = mm_strdup("0");
+					fprintf(yyout, "%s,", get_dtype(results->value));
+					ECPGdump_a_type(yyout, v->name, v->type, v->brace_level, NULL, NULL, -1, NULL, NULL, str_zero, NULL, NULL);
+					free(str_zero);
+				}
 				break;
 
 			default:
diff --git a/src/interfaces/ecpg/preproc/pgc.l b/src/interfaces/ecpg/preproc/pgc.l
index c70f298..0453409 100644
--- a/src/interfaces/ecpg/preproc/pgc.l
+++ b/src/interfaces/ecpg/preproc/pgc.l
@@ -27,7 +27,7 @@
 extern YYSTYPE yylval;
 
 static int		xcdepth = 0;	/* depth of nesting in slash-star comments */
-static char	   *dolqstart;		/* current $foo$ quote start string */
+static char	   *dolqstart = NULL;	/* current $foo$ quote start string */
 static YY_BUFFER_STATE scanbufhandle;
 static char *scanbuf;
 
@@ -550,6 +550,8 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifndef}|{import})(.*\\{space})*.
 			}
 <SQL>{dolqdelim} {
 				token_start = yytext;
+				if (dolqstart)
+					free(dolqstart);
 				dolqstart = mm_strdup(yytext);
 				BEGIN(xdolq);
 				startlit();
diff --git a/src/interfaces/ecpg/preproc/variable.c b/src/interfaces/ecpg/preproc/variable.c
index 2ad7b5d..bb4b664 100644
--- a/src/interfaces/ecpg/preproc/variable.c
+++ b/src/interfaces/ecpg/preproc/variable.c
@@ -437,11 +437,13 @@ remove_variable_from_list(struct arguments ** list, struct variable * var)
 void
 dump_variables(struct arguments * list, int mode)
 {
-	char	   *str_zero = mm_strdup("0");
+	char	   *str_zero;
 
 	if (list == NULL)
 		return;
 
+	str_zero = mm_strdup("0");
+
 	/*
 	 * The list is build up from the beginning so lets first dump the end of
 	 * the list: