Fix memory leak in keys initialization

Previous to this commit, a strdup took place for every key name
including those that were replaced with customized key names later on
while never calling free on the pointer returned by strdup.

This fix only calls strdup for key names that are not replaced with
custom key names.

Found with ASAN.

Signed-off-by: Max Kunzelmann <max@mxzero.net>
Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>

src/keys.c

@@ -162,6 +162,47 @@ static struct keydef_s keydef[NBVKEYS] = {
  */
 static char *keynames[KEY_MAX];
 
+/* Maps a key code to a custom key name */
+struct custom_keyname_s {
+	int keycode;
+	char* keyname;
+};
+
+#define CUSTOM_KEYS 26
+
+/*
+ * Customized key names with calcurse short forms
+ */
+static struct custom_keyname_s custom_keynames[CUSTOM_KEYS] = {
+	{ TAB, "TAB" },
+	{ RETURN, "RET" },
+	{ ESCAPE, "ESC" },
+	{ SPACE, "SPC" },
+	{ KEY_UP, "UP" },
+	{ KEY_DOWN, "DWN" },
+	{ KEY_LEFT, "LFT" },
+	{ KEY_RIGHT, "RGT" },
+	{ KEY_HOME, "HOM" },
+	{ KEY_END, "END" },
+	{ KEY_NPAGE, "PgD" },
+	{ KEY_PPAGE, "PgU" },
+	{ KEY_IC, "INS" },
+	{ KEY_DC, "DEL" },
+	{ KEY_F(1), "F1" },
+	{ KEY_F(2), "F2" },
+	{ KEY_F(3), "F3" },
+	{ KEY_F(4), "F4" },
+	{ KEY_F(5), "F5" },
+	{ KEY_F(6), "F6" },
+	{ KEY_F(7), "F7" },
+	{ KEY_F(8), "F8" },
+	{ KEY_F(9), "F9" },
+	{ KEY_F(10), "F10" },
+	{ KEY_F(11), "F11" },
+	{ KEY_F(12), "F12" },
+};
+
+
 static void dump_intro(FILE * fd)
 {
 	const char *intro =
@@ -175,6 +216,16 @@ static void dump_intro(FILE * fd)
 	fprintf(fd, "%s\n", intro);
 }
 
+static bool is_customized(int c) {
+	int i;
+
+	for (i = 0; i < CUSTOM_KEYS; i++)
+		if (c == custom_keynames[i].keycode)
+			return true;
+
+	return false;
+}
+
 void keys_init(void)
 {
 	int i;
@@ -193,40 +244,20 @@ void keys_init(void)
 
 	 /* Insertion of ncurses names in the ASCII range ...  */
 	for (i = 1; i < 128; i++)
-		if ((cp = keyname(i)))
-			keynames[i] = mem_strdup(cp);
+		if (!is_customized(i))
+			if ((cp = keyname(i)))
+				keynames[i] = mem_strdup(cp);
+
 	/* ... and for the ncurses pseudo-characters. */
 	for (i = KEY_MIN; i < KEY_MAX; i++)
-		if ((cp = keyname(i)))
-			keynames[i] = mem_strdup(cp);
+		if (!is_customized(i))
+			if ((cp = keyname(i)))
+				keynames[i] = mem_strdup(cp);
 
 	/* Replace some with calcurse short forms. */
-	keynames[TAB] =		"TAB";
-	keynames[RETURN] =	"RET";
-	keynames[ESCAPE] =	"ESC";
-	keynames[SPACE] =	"SPC";
-	keynames[KEY_UP] =	"UP";
-	keynames[KEY_DOWN] =	"DWN";
-	keynames[KEY_LEFT] =	"LFT";
-	keynames[KEY_RIGHT] =	"RGT";
-	keynames[KEY_HOME] =	"HOM";
-	keynames[KEY_END] =	"END";
-	keynames[KEY_NPAGE] =	"PgD";
-	keynames[KEY_PPAGE] =	"PgU";
-	keynames[KEY_IC] =	"INS";
-	keynames[KEY_DC] =	"DEL";
-	keynames[KEY_F(1)] =	"F1";
-	keynames[KEY_F(2)] =	"F2";
-	keynames[KEY_F(3)] =	"F3";
-	keynames[KEY_F(4)] =	"F4";
-	keynames[KEY_F(5)] =	"F5";
-	keynames[KEY_F(6)] =	"F6";
-	keynames[KEY_F(7)] =	"F7";
-	keynames[KEY_F(8)] =	"F8";
-	keynames[KEY_F(9)] =	"F9";
-	keynames[KEY_F(10)] =	"F10";
-	keynames[KEY_F(11)] =	"F11";
-	keynames[KEY_F(12)] =	"F12";
+	for (i = 0; i < CUSTOM_KEYS; i++) {
+		keynames[custom_keynames[i].keycode] = custom_keynames[i].keyname;
+	}
 }
 
 static void key_free(char *s)