[hackers] [scc] [driver] set unassigned fds to -1 || Quentin Rameau

[git]

commit fd8427efdb2eb026dcc042d85a53af51d5d9e37d
Author:     Quentin Rameau <quinq@fifth.space>
AuthorDate: Wed Jun 15 15:57:49 2016 +0200
Commit:     Quentin Rameau <quinq@fifth.space>
CommitDate: Wed Jun 15 18:50:46 2016 +0200

    [driver] set unassigned fds to -1
    
    Although pipe() would never return fds < 2 in our case, it's more
    correct to check against negative fd.
    Thanks to Hiltjo for the suggestion!

diff --git a/driver/posix/scc.c b/driver/posix/scc.c
index a81eef4..92a14b0 100644
--- a/driver/posix/scc.c
+++ b/driver/posix/scc.c
@@ -196,7 +196,7 @@ settool(int tool, char *infile, int nexttool)
 {
        struct tool *t = &tools[tool];
        int i, fds[2];
-       static int fdin;
+       static int fdin = -1;
 
        switch (tool) {
        case TEEIR:
@@ -233,9 +233,9 @@ settool(int tool, char *infile, int nexttool)
                break;
        }
 
-       if (fdin) {
+       if (fdin > -1) {
                t->in = fdin;
-               fdin = 0;
+               fdin = -1;
        } else if (infile) {
                addarg(tool, xstrdup(infile));
        }
@@ -261,18 +261,18 @@ spawn(int tool)
        case -1:
                die("scc: %s: %s", t->bin, strerror(errno));
        case 0:
-               if (t->out)
+               if (t->out > -1)
                        dup2(t->out, 1);
-               if (t->in)
+               if (t->in > -1)
                        dup2(t->in, 0);
                execvp(t->cmd, t->args);
                fprintf(stderr, "scc: execvp %s: %s\n",
                        t->cmd, strerror(errno));
                _exit(1);
        default:
-               if (t->in)
+               if (t->in > -1)
                        close(t->in);
-               if (t->out)
+               if (t->out > -1)
                        close(t->out);
                break;
        }
@@ -317,8 +317,8 @@ validatetools(void)
                        t->nargs = t->nparams;
                        t->pid = 0;
                        t->error = 0;
-                       t->in = 0;
-                       t->out = 0;
+                       t->in = -1;
+                       t->out = -1;
                }
        }
 }