lc-compile: Ensure file pointer is initialised at declaration

peter-b · peter-b · commit 416aa06072da · 2017-03-01T11:41:01.000Z
In `GetFilenameOfPosition()`, it is possible for `GetFileOfPosition()`
not to provide a valid `MCFileRef`.  In that case, `GetFileOfPath()`
would dereference uninitialised value as a pointer.
diff --git a/toolchain/libcompile/src/position.c b/toolchain/libcompile/src/position.c
@@ -95,7 +95,7 @@ void GetFileOfPosition(long p_position, FileRef *r_file)
 
 void GetFilenameOfPosition(long p_position, const char **r_filename)
 {
-    FileRef t_file;
+    FileRef t_file = NULL;
     GetFileOfPosition(p_position, &t_file);
     GetFilePath(t_file, r_filename);
 }

Original file line number	Diff line number	Diff line change
`@@ -95,7 +95,7 @@ void GetFileOfPosition(long p_position, FileRef *r_file)`
`95`	`95`
`96`	`96`	`void GetFilenameOfPosition(long p_position, const char **r_filename)`
`97`	`97`	`{`
`98`		`- FileRef t_file;`
	`98`	`+ FileRef t_file = NULL;`
`99`	`99`	`GetFileOfPosition(p_position, &t_file);`
`100`	`100`	`GetFilePath(t_file, r_filename);`
`101`	`101`	`}`