[PATCH 04/12] pager: explicitly cast away strchr() constness

[Jeff King <peff@peff.net>]

When we do:

  char *cp = strchr(argv[i], '=');

it implicitly removes the constness from argv[i]. We need "cp" to remain
writable (since we overwrite it with a NUL). In theory we should be able
to drop the const from argv[i], because it is a sub-pointer into our
duplicated pager_env variable.

But we get it from split_cmdline(), which uses the traditional "const
char **" type for argv. This is overly limiting, but changing it would
be awkward for all the other callers of split_cmdline().

Let's do an explicit cast with a note about why it is OK. This is enough
to silence compiler warnings about the implicit const problems.

Signed-off-by: Jeff King <peff@peff.net>
---
 pager.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pager.c b/pager.c
index 5531fff50e..801ba392f2 100644
--- a/pager.c
+++ b/pager.c
@@ -118,7 +118,8 @@ static void setup_pager_env(struct strvec *env)
 			split_cmdline_strerror(n));
 
 	for (i = 0; i < n; i++) {
-		char *cp = strchr(argv[i], '=');
+		/* we know this is writable because it was split from pager_env */
+		char *cp = strchr((char *)argv[i], '=');
 
 		if (!cp)
 			die("malformed build-time PAGER_ENV");
-- 
2.53.0.1136.gd760fbd4a0