Add config read fns with controlled error behavior

This adds `git_config__lookup_entry` which will look up a key in
a config and return either the entry or NULL if the key was not
present.  Optionally, it can either suppress all errors or can
return them (although not finding the key is not an error for this
function).  Unlike other accessors, this does not normalize the
config key string, so it must only be used when the key is known
to be in normalized form (i.e. all lower-case before the first dot
and after the last dot, with no invalid characters).

This also adds three high-level helper functions to look up config
values with no errors and a fallback value.  The three functions
are for string, bool, and int values, and will resort to the
fallback value for any error that arises.  They are:

* `git_config__get_string_force`
* `git_config__get_bool_force`
* `git_config__get_int_force`

None of them normalize the config `key` either, so they can only
be used for internal cases where the key is known to be in normal
format.

1 files changed, 9 insertions, 30 deletions

diff --git a/src/diff.c b/src/diff.c
index 4c33a0213..53a8f4638 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -304,26 +304,6 @@ bool git_diff_delta__should_skip(
 }
 
 
-static int config_bool(git_config *cfg, const char *name, int defvalue)
-{
-	int val = defvalue;
-
-	if (git_config_get_bool(&val, cfg, name) < 0)
-		giterr_clear();
-
-	return val;
-}
-
-static int config_int(git_config *cfg, const char *name, int defvalue)
-{
-	int val = defvalue;
-
-	if (git_config_get_int32(&val, cfg, name) < 0)
-		giterr_clear();
-
-	return val;
-}
-
 static const char *diff_mnemonic_prefix(
 	git_iterator_type_t type, bool left_side)
 {
@@ -422,8 +402,8 @@ static int diff_list_apply_options(
 		diff->opts.flags |= GIT_DIFF_INCLUDE_UNTRACKED;
 
 	/* load config values that affect diff behavior */
-	if (git_repository_config__weakptr(&cfg, repo) < 0)
-		return -1;
+	if ((val = git_repository_config__weakptr(&cfg, repo)) < 0)
+		return val;
 
 	if (!git_repository__cvar(&val, repo, GIT_CVAR_SYMLINKS) && val)
 		diff->diffcaps = diff->diffcaps | GIT_DIFFCAPS_HAS_SYMLINKS;
@@ -445,7 +425,7 @@ static int diff_list_apply_options(
 
 	/* If not given explicit `opts`, check `diff.xyz` configs */
 	if (!opts) {
-		int context = config_int(cfg, "diff.context", 3);
+		int context = git_config__get_int_force(cfg, "diff.context", 3);
 		diff->opts.context_lines = context >= 0 ? (uint16_t)context : 3;
 
 		/* add other defaults here */
@@ -460,12 +440,11 @@ static int diff_list_apply_options(
 
 	/* if ignore_submodules not explicitly set, check diff config */
 	if (diff->opts.ignore_submodules <= 0) {
-		const char *str;
+		const git_config_entry *entry;
+		git_config__lookup_entry(&entry, cfg, "diff.ignoresubmodules", true);
 
-		if (git_config_get_string(&str , cfg, "diff.ignoreSubmodules") < 0)
-			giterr_clear();
-		else if (str != NULL &&
-			git_submodule_parse_ignore(&diff->opts.ignore_submodules, str) < 0)
+		if (entry && git_submodule_parse_ignore(
+				&diff->opts.ignore_submodules, entry->value) < 0)
 			giterr_clear();
 	}
 
@@ -474,9 +453,9 @@ static int diff_list_apply_options(
 		const char *use_old = DIFF_OLD_PREFIX_DEFAULT;
 		const char *use_new = DIFF_NEW_PREFIX_DEFAULT;
 
-		if (config_bool(cfg, "diff.noprefix", 0)) {
+		if (git_config__get_bool_force(cfg, "diff.noprefix", 0))
 			use_old = use_new = "";
-		} else if (config_bool(cfg, "diff.mnemonicprefix", 0)) {
+		else if (git_config__get_bool_force(cfg, "diff.mnemonicprefix", 0)) {
 			use_old = diff_mnemonic_prefix(diff->old_src, true);
 			use_new = diff_mnemonic_prefix(diff->new_src, false);
 		}