[hackers] [sbase] ed: Use strlcpy/strlcat to construct the scratch filename || sin

[git]

commit 3300d5d47a054bd2615db0f99e1478808ec88032
Author:     sin <s...@2f30.org>
AuthorDate: Sat Jan 2 09:44:06 2016 +0000
Commit:     sin <s...@2f30.org>
CommitDate: Sat Jan 2 09:46:48 2016 +0000

    ed: Use strlcpy/strlcat to construct the scratch filename

diff --git a/ed.c b/ed.c
index 62f8477..ed55581 100644
--- a/ed.c
+++ b/ed.c
@@ -335,12 +335,12 @@ setscratch()
        clearundo();
        if ((dir = getenv("TMPDIR")) == NULL)
                dir = "/tmp/";
-       if (strlen(dir) + sizeof("ed.XXXXXX") > FILENAME_MAX)
-               error("incorrect scratch file name");
-       strcat(strcpy(tmpname, dir), "ed.XXXXX");
-       if ((scratch = mkstemp(tmpname)) < 0) {
+       if (strlcpy(tmpname, dir, sizeof(tmpname)) >= sizeof(tmpname))
+               error("scratch file name too long");
+       if (strlcat(tmpname, "ed.XXXXXX", sizeof(tmpname)) >= sizeof(tmpname))
+               error("scratch file name too long");
+       if ((scratch = mkstemp(tmpname)) < 0)
                error("failed to create scratch file");
-       }
        if ((k = makeline("", NULL)))
                error("input/output error in scratch file");
        relink(k, k, k, k);