Bring along a trailing null when guessing the path to the program under test

cat/test/main.c

@@ -2659,7 +2659,7 @@ main(int argc, char **argv)
 			exit(1);
 		}
 		memmove(testprogdir + strlen(pwd) + 1, testprogdir,
-		    strlen(testprogdir));
+		    strlen(testprogdir) + 1);
 		memcpy(testprogdir, pwd, strlen(pwd));
 		testprogdir[strlen(pwd)] = '/';
 	}

cpio/test/main.c

@@ -2660,7 +2660,7 @@ main(int argc, char **argv)
 			exit(1);
 		}
 		memmove(testprogdir + strlen(pwd) + 1, testprogdir,
-		    strlen(testprogdir));
+		    strlen(testprogdir) + 1);
 		memcpy(testprogdir, pwd, strlen(pwd));
 		testprogdir[strlen(pwd)] = '/';
 	}

libarchive/test/main.c

@@ -2658,7 +2658,7 @@ main(int argc, char **argv)
 			exit(1);
 		}
 		memmove(testprogdir + strlen(pwd) + 1, testprogdir,
-		    strlen(testprogdir));
+		    strlen(testprogdir) + 1);
 		memcpy(testprogdir, pwd, strlen(pwd));
 		testprogdir[strlen(pwd)] = '/';
 	}

tar/test/main.c

@@ -2660,7 +2660,7 @@ main(int argc, char **argv)
 			exit(1);
 		}
 		memmove(testprogdir + strlen(pwd) + 1, testprogdir,
-		    strlen(testprogdir));
+		    strlen(testprogdir) + 1);
 		memcpy(testprogdir, pwd, strlen(pwd));
 		testprogdir[strlen(pwd)] = '/';
 	}