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, 15 insertions, 20 deletions

diff --git a/src/diff_tform.c b/src/diff_tform.c
index 702e43bd3..2f94b2e77 100644
--- a/src/diff_tform.c
+++ b/src/diff_tform.c
@@ -13,6 +13,7 @@
 #include "hashsig.h"
 #include "path.h"
 #include "fileops.h"
+#include "config.h"
 
 static git_diff_delta *diff_delta__dup(
 	const git_diff_delta *d, git_pool *pool)
@@ -290,19 +291,16 @@ static int normalize_find_opts(
 	if (!given ||
 		 (given->flags & GIT_DIFF_FIND_ALL) == GIT_DIFF_FIND_BY_CONFIG)
 	{
-		const char *val = NULL;
-
-		if (git_config_get_string(&val, cfg, "diff.renames") < 0)
-			giterr_clear();
-		else if (val) {
-			int boolval;
-			if (!git__parse_bool(&boolval, val) && !boolval) {
-				/* do nothing */
-			} else if (!strcasecmp(val, "copies") || !strcasecmp(val, "copy"))
-				opts->flags |= (GIT_DIFF_FIND_RENAMES | GIT_DIFF_FIND_COPIES);
-			else
-				opts->flags |= GIT_DIFF_FIND_RENAMES;
-		}
+		const char *rule =
+			git_config__get_string_force(cfg, "diff.renames", "true");
+		int boolval;
+
+		if (!git__parse_bool(&boolval, rule) && !boolval)
+			/* don't set FIND_RENAMES if bool value is false */;
+		else if (!strcasecmp(rule, "copies") || !strcasecmp(rule, "copy"))
+			opts->flags |= GIT_DIFF_FIND_RENAMES | GIT_DIFF_FIND_COPIES;
+		else
+			opts->flags |= GIT_DIFF_FIND_RENAMES;
 	}
 
 	/* some flags imply others */
@@ -343,14 +341,11 @@ static int normalize_find_opts(
 #undef USE_DEFAULT
 
 	if (!opts->rename_limit) {
-		int32_t limit = 0;
-
-		opts->rename_limit = DEFAULT_RENAME_LIMIT;
+		opts->rename_limit = git_config__get_int_force(
+			cfg, "diff.renamelimit", DEFAULT_RENAME_LIMIT);
 
-		if (git_config_get_int32(&limit, cfg, "diff.renameLimit") < 0)
-			giterr_clear();
-		else if (limit > 0)
-			opts->rename_limit = limit;
+		if (opts->rename_limit <= 0)
+			opts->rename_limit = DEFAULT_RENAME_LIMIT;
 	}
 
 	/* assign the internal metric with whitespace flag as payload */