[PATCH libinput] Fix to avoid use of undefined pointer values.

[Jon A. Cruz]

If asprintf fails for any reason, the contents of the pointer
are undefined. While some platforms set it to NULL, there is no
guarantee that all will.

Signed-off-by: Jon A. Cruz <jonc at osg.samsung.com>
---
 tools/libinput-list-devices.c | 59 ++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 26 deletions(-)

diff --git a/tools/libinput-list-devices.c b/tools/libinput-list-devices.c
index 6625173..b492e1d 100644
--- a/tools/libinput-list-devices.c
+++ b/tools/libinput-list-devices.c
@@ -120,24 +120,27 @@ calibration_default(struct libinput_device *device)
 	float calibration[6];
 
 	if (!libinput_device_config_calibration_has_matrix(device)) {
-		asprintf(&str, "n/a");
+		if (asprintf(&str, "n/a") == -1)
+			str = NULL;
 		return str;
 	}
 
 	if (libinput_device_config_calibration_get_default_matrix(device,
 						  calibration) == 0) {
-		asprintf(&str, "identity matrix");
+		if (asprintf(&str, "identity matrix") == -1)
+			str = NULL;
 		return str;
 	}
 
-	asprintf(&str,
-		 "%.2f %.2f %.2f %.2f %.2f %.2f",
-		 calibration[0],
-		 calibration[1],
-		 calibration[2],
-		 calibration[3],
-		 calibration[4],
-		 calibration[5]);
+	if (asprintf(&str,
+		     "%.2f %.2f %.2f %.2f %.2f %.2f",
+		     calibration[0],
+		     calibration[1],
+		     calibration[2],
+		     calibration[3],
+		     calibration[4],
+		     calibration[5]) == -1)
+		str = NULL;
 	return str;
 }
 
@@ -150,20 +153,22 @@ scroll_defaults(struct libinput_device *device)
 
 	scroll_methods = libinput_device_config_scroll_get_methods(device);
 	if (scroll_methods == LIBINPUT_CONFIG_SCROLL_NO_SCROLL) {
-		asprintf(&str, "none");
+		if (asprintf(&str, "none") == -1)
+			str = NULL;
 		return str;
 	}
 
 	method = libinput_device_config_scroll_get_default_method(device);
 
-	asprintf(&str,
-		 "%s%s%s%s%s%s",
-		 (method == LIBINPUT_CONFIG_SCROLL_2FG) ? "*" : "",
-		 (scroll_methods & LIBINPUT_CONFIG_SCROLL_2FG) ? "two-finger " : "",
-		 (method == LIBINPUT_CONFIG_SCROLL_EDGE) ? "*" : "",
-		 (scroll_methods & LIBINPUT_CONFIG_SCROLL_EDGE) ? "edge " : "",
-		 (method == LIBINPUT_CONFIG_SCROLL_ON_BUTTON_DOWN) ? "*" : "",
-		 (scroll_methods & LIBINPUT_CONFIG_SCROLL_ON_BUTTON_DOWN) ? "button" : "");
+	if (asprintf(&str,
+		     "%s%s%s%s%s%s",
+		     (method == LIBINPUT_CONFIG_SCROLL_2FG) ? "*" : "",
+		     (scroll_methods & LIBINPUT_CONFIG_SCROLL_2FG) ? "two-finger " : "",
+		     (method == LIBINPUT_CONFIG_SCROLL_EDGE) ? "*" : "",
+		     (scroll_methods & LIBINPUT_CONFIG_SCROLL_EDGE) ? "edge " : "",
+		     (method == LIBINPUT_CONFIG_SCROLL_ON_BUTTON_DOWN) ? "*" : "",
+		     (scroll_methods & LIBINPUT_CONFIG_SCROLL_ON_BUTTON_DOWN) ? "button" : "") == -1)
+		str = NULL;
 	return str;
 }
 
@@ -176,17 +181,19 @@ click_defaults(struct libinput_device *device)
 
 	click_methods = libinput_device_config_click_get_methods(device);
 	if (click_methods == LIBINPUT_CONFIG_CLICK_METHOD_NONE) {
-		asprintf(&str, "none");
+		if (asprintf(&str, "none") == -1)
+			str = NULL;
 		return str;
 	}
 
 	method = libinput_device_config_click_get_default_method(device);
-	asprintf(&str,
-		 "%s%s%s%s",
-		 (method == LIBINPUT_CONFIG_CLICK_METHOD_BUTTON_AREAS) ? "*" : "",
-		 (click_methods & LIBINPUT_CONFIG_CLICK_METHOD_BUTTON_AREAS) ? "button-areas " : "",
-		 (method == LIBINPUT_CONFIG_CLICK_METHOD_CLICKFINGER) ? "*" : "",
-		 (click_methods & LIBINPUT_CONFIG_CLICK_METHOD_CLICKFINGER) ? "clickfinger " : "");
+	if (asprintf(&str,
+		     "%s%s%s%s",
+		     (method == LIBINPUT_CONFIG_CLICK_METHOD_BUTTON_AREAS) ? "*" : "",
+		     (click_methods & LIBINPUT_CONFIG_CLICK_METHOD_BUTTON_AREAS) ? "button-areas " : "",
+		     (method == LIBINPUT_CONFIG_CLICK_METHOD_CLICKFINGER) ? "*" : "",
+		     (click_methods & LIBINPUT_CONFIG_CLICK_METHOD_CLICKFINGER) ? "clickfinger " : "") == -1)
+		str = NULL;
 	return str;
 }
 
-- 
2.1.0