From 08a22f2eea8b906e0c5e050a3acec4f337824d7d Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Tue, 1 Nov 2016 12:33:55 +0100
Subject: [PATCH] ifcfg-rh: avoid copying temporary value after unescaping

svUnescape() can return a pointer to the input argument
(if the input argument requires no unescaping or truncation).

That is actually the predominant case because most often we
store values that don't require escaping.

Optimize for that case.
---
 src/settings/plugins/ifcfg-rh/shvar.c | 78 +++++++++++++++++----------
 1 file changed, 50 insertions(+), 28 deletions(-)

diff --git a/src/settings/plugins/ifcfg-rh/shvar.c b/src/settings/plugins/ifcfg-rh/shvar.c
index 381b4edddc..f7e4ce4ffb 100644
--- a/src/settings/plugins/ifcfg-rh/shvar.c
+++ b/src/settings/plugins/ifcfg-rh/shvar.c
@@ -751,19 +751,16 @@ line_construct (const char *key, const char *value)
 
 /*****************************************************************************/
 
-/* svGetValue() is identical to svGetValueString() except that
- * svGetValueString() will never return an empty value (but %NULL instead).
- * svGetValue() will return empty values if that is the value for the @key. */
-char *
-svGetValue (shvarFile *s, const char *key)
+static const char *
+_svGetValue (shvarFile *s, const char *key, char **to_free)
 {
 	const GList *current;
 	const char *line_val;
 	const char *last_val = NULL;
-	char *to_free;
 
-	g_return_val_if_fail (s != NULL, NULL);
-	g_return_val_if_fail (key != NULL, NULL);
+	nm_assert (s);
+	nm_assert (_shell_is_name (key));
+	nm_assert (to_free);
 
 	current = s->lineList;
 	while ((current = shlist_find (current, key, &line_val))) {
@@ -771,11 +768,28 @@ svGetValue (shvarFile *s, const char *key)
 		current = current->next;
 	}
 
-	if (!last_val)
+	if (!last_val) {
+		*to_free = NULL;
 		return NULL;
+	}
 
-	line_val = svUnescape (last_val, &to_free);
-	return to_free ?: g_strdup (line_val);
+	return svUnescape (last_val, to_free);
+}
+
+/* svGetValue() is identical to svGetValueString() except that
+ * svGetValueString() will never return an empty value (but %NULL instead).
+ * svGetValue() will return empty values if that is the value for the @key. */
+char *
+svGetValue (shvarFile *s, const char *key)
+{
+	const char *value;
+	char *to_free;
+
+	g_return_val_if_fail (s != NULL, NULL);
+	g_return_val_if_fail (key != NULL, NULL);
+
+	value = _svGetValue (s, key, &to_free);
+	return to_free ?: (value ? g_strdup (value) : NULL);
 }
 
 /* Get the value associated with the key, and leave the current pointer
@@ -785,14 +799,19 @@ svGetValue (shvarFile *s, const char *key)
 char *
 svGetValueString (shvarFile *s, const char *key)
 {
-	char *value;
+	char *to_free;
+	const char *value;
 
-	value = svGetValue (s, key);
-	if (value && !*value) {
-		g_free (value);
+	value = _svGetValue (s, key, &to_free);
+	if (!value) {
+		nm_assert (!to_free);
 		return NULL;
 	}
-	return value;
+	if (!value[0]) {
+		g_free (to_free);
+		return NULL;
+	}
+	return to_free ?: g_strdup (value);
 }
 
 /* svGetValueBoolean:
@@ -807,10 +826,11 @@ svGetValueString (shvarFile *s, const char *key)
 gint
 svGetValueBoolean (shvarFile *s, const char *key, gint fallback)
 {
-	gs_free char *tmp = NULL;
+	gs_free char *to_free = NULL;
+	const char *value;
 
-	tmp = svGetValueString (s, key);
-	return svParseBoolean (tmp, fallback);
+	value = _svGetValue (s, key, &to_free);
+	return svParseBoolean (value, fallback);
 }
 
 /* svGetValueInt64:
@@ -826,22 +846,24 @@ svGetValueBoolean (shvarFile *s, const char *key, gint fallback)
 gint64
 svGetValueInt64 (shvarFile *s, const char *key, guint base, gint64 min, gint64 max, gint64 fallback)
 {
-	char *tmp;
+	char *to_free;
+	const char *value;
 	gint64 result;
 	int errsv;
 
-	tmp = svGetValue (s, key);
-	if (!tmp) {
+	value = _svGetValue (s, key, &to_free);
+	if (!value) {
+		nm_assert (!to_free);
 		errno = 0;
 		return fallback;
 	}
 
-	result = _nm_utils_ascii_str_to_int64 (tmp, base, min, max, fallback);
-	errsv = errno;
-
-	g_free (tmp);
-
-	errno = errsv;
+	result = _nm_utils_ascii_str_to_int64 (value, base, min, max, fallback);
+	if (to_free) {
+		errsv = errno;
+		g_free (to_free);
+		errno = errsv;
+	}
 	return result;
 }