In the Subversion example, this is the place where Sally asks for a lock. But Mercurial doesn’t support lock.

Harry updates his repository instance.

lottery harry$ hg pull
pulling from http://server.futilisoft.com:8000/
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files
(run 'hg update' to get a working copy)

lottery harry$ hg update
0 files updated, 0 files merged, 387 files removed, 0 files unresolved

lottery harry$ ls -l
total 8
-rw-r--r--  1 harry  staff   66 May 17 11:47 Makefile
drwxr-xr-x  3 harry  staff  102 May 17 13:58 src

Sod it! That Sally must have her landlady face on. She’s deleted all his email code! Harry decides to indent^[24] pb.c.

lottery harry$ indent src/pb.c

lottery harry$ hg st
M src/pb.c
? pb.c.BAK

This is getting shambolic. Harry calms down and reverts the changes.

lottery harry$ hg revert src/pb.c

lottery harry$ hg st
? pb.c.BAK
? src/pb.c.orig

lottery harry$ rm pb.c.BAK src/pb.c.orig

Sally has decided to eliminate uses of atoi(), which is deprecated.

lottery sally$ hg diff
diff -r a3a4497e7ff6 src/pb.c
--- a/src/pb.c  Tue May 17 14:04:44 2011 -0500
+++ b/src/pb.c  Tue May 17 14:10:51 2011 -0500
@@ -43,7 +43,14 @@
     int white_balls[5];
     for (int i=0; i<5; i++)
     {
-        white_balls[i] = atoi(argv[1+i]);
+        char* endptr = NULL;
+        long val = strtol(argv[1+i], &endptr, 10);
+        if (*endptr)
+        {
+            fprintf(stderr, "Invalid arguments\n");
+            return -1;
+        }
+        white_balls[i] = (int) val;
     }
 
     int result = calculate_result(white_balls, power_ball);

lottery sally$ make
gcc -std=c99 -Wall -Wextra -Werror pb.c -o pb

lottery sally$ ./pb 1 2 3 4 5 6
0 percent chance of winning

lottery sally$ ./pb 1 2 3e 4 5 6
Invalid arguments

And she commits her changes, easy as dialing BR-549.

lottery sally$ hg commit -m "use strtol. atoi is deprecated."

lottery sally$ hg push
pushing to http://server.futilisoft.com:8000/
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files