Make improvements

- Expand redbean UNIX module
- Expand redbean documentation
- Ensure Lua copyright is embedded in binary
- Increase the PATH_MAX limit especially on NT
- Use column major sorting for linenoise completions
- Fix some suboptimalities in redbean's new UNIX API
- Figured out right flags for Multics newline in raw mode

test/libc/calls/execve_test.c

@@ -29,6 +29,13 @@ void SetUp(void) {
     } else {
       exit(7);
     }
+  } else if (getenv("_WEIRDENV")) {
+    for (char **e = environ; *e; ++e) {
+      if (!strcmp(*e, "WEIRD")) {
+        exit(0);
+      }
+    }
+    exit(7);
   }
 }
 
@@ -47,3 +54,20 @@ TEST(execve, testWeirdAnsiC89emptyArgv) {
   EXPECT_TRUE(WIFEXITED(ws));
   EXPECT_EQ(0, WEXITSTATUS(ws));
 }
+
+TEST(execve, testWeirdEnvironmentVariable) {
+  char *prog;
+  int pid, ws;
+  if (IsWindows()) return;
+  if (IsOpenbsd()) return;
+  prog = GetProgramExecutableName();
+  ASSERT_NE(-1, (pid = fork()));
+  if (!pid) {
+    execve(prog, (char *const[]){prog, 0},
+           (char *const[]){"_WEIRDENV=1", "WEIRD", 0});
+    _Exit(127);
+  }
+  ASSERT_NE(-1, wait(&ws));
+  EXPECT_TRUE(WIFEXITED(ws));
+  EXPECT_EQ(0, WEXITSTATUS(ws));
+}