config: drop git_config_get_string_const()

As evidenced by the leak fixes in the previous commit, the "const" in
git_config_get_string_const() clearly misleads people into thinking that
it does not allocate a copy of the string. We can fix this by renaming
it, but it's easier still to just drop it. Of the four remaining
callers:

  - The one in git_config_parse_expiry() still needs to allocate, since
    that's what its callers expect. We can just use the non-const
    version and cast our pointer. Slightly ugly, but the damage is
    contained in one spot.

  - The two in apply are writing to global "const char *" variables, and
    need to continue allocating. We often mark these as const because we
    assign default string literals to them. But in this case we don't do
    that, so we can just declare them as real "char *" pointers and use
    the non-const version.

  - The call in checkout doesn't actually need a copy; it can just use
    the non-allocating "tmp" version of the function.

The function is also mentioned in the MyFirstContribution document. We
can swap that call out for the non-allocating "tmp" variant, which fits
well in the example given.

We'll drop the "configset" and "repo" variants, as well (which are
unused).

Note that this frees up the "const" name, so we could rename the "tmp"
variant back to that. But let's give some time for topics in flight to
adapt to the new code before doing so (if we do it too soon, the
function semantics will change but the compiler won't alert us).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 10 deletions

diff --git a/config.h b/config.h
index a75b22e..91cdfbf 100644
--- a/config.h
+++ b/config.h
@@ -458,7 +458,6 @@ void git_configset_clear(struct config_set *cs);
  */
 int git_configset_get_value(struct config_set *cs, const char *key, const char **dest);
 
-int git_configset_get_string_const(struct config_set *cs, const char *key, const char **dest);
 int git_configset_get_string(struct config_set *cs, const char *key, char **dest);
 int git_configset_get_string_tmp(struct config_set *cs, const char *key, const char **dest);
 int git_configset_get_int(struct config_set *cs, const char *key, int *dest);
@@ -475,8 +474,6 @@ int repo_config_get_value(struct repository *repo,
 			  const char *key, const char **value);
 const struct string_list *repo_config_get_value_multi(struct repository *repo,
 						      const char *key);
-int repo_config_get_string_const(struct repository *repo,
-				 const char *key, const char **dest);
 int repo_config_get_string(struct repository *repo,
 			   const char *key, char **dest);
 int repo_config_get_string_tmp(struct repository *repo,
@@ -532,16 +529,10 @@ void git_config_clear(void);
  * error message and returns -1. When the configuration variable `key` is
  * not found, returns 1 without touching `dest`.
  */
-int git_config_get_string_const(const char *key, const char **dest);
-
-/**
- * Similar to `git_config_get_string_const`, except that retrieved value
- * copied into the `dest` parameter is a mutable string.
- */
 int git_config_get_string(const char *key, char **dest);
 
 /**
- * Similar to `git_config_get_string_const`, but does not allocate any new
+ * Similar to `git_config_get_string`, but does not allocate any new
  * memory; on success `dest` will point to memory owned by the config
  * machinery, which could be invalidated if it is discarded and reloaded.
  */