Subject: [PATCH v5 1/2] config: let git_config_parse_key() validate quietly

From: "Harald Nordgren via GitGitGadget" <[email-masked]>
Date: Tue, 02 Jun 2026 13:39:16 +0000

From: Harald Nordgren <[email-masked]>

Add a "quiet" parameter that suppresses the error() calls, and let
store_key be NULL to skip the canonical-copy allocation.  Existing
callers pass 0 for quiet.

Signed-off-by: Harald Nordgren <[email-masked]>
---
 builtin/config.c   |  2 +-
 config.c           | 34 ++++++++++++++++++++++------------
 config.h           |  2 +-
 submodule-config.c |  2 +-
 4 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/builtin/config.c b/builtin/config.c
index cf4ba0f7cc..b3188cd8d4 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -555,7 +555,7 @@ static int get_value(const struct config_location_options *opts,
 			goto free_strings;
 		}
 	} else {
-		if (git_config_parse_key(key_, &key, NULL)) {
+		if (git_config_parse_key(key_, &key, NULL, 0)) {
 			ret = CONFIG_INVALID_KEY;
 			goto free_strings;
 		}
diff --git a/config.c b/config.c
index a1b92fe083..81b31c5155 100644
--- a/config.c
+++ b/config.c
@@ -536,11 +536,14 @@ static inline int iskeychar(int c)
  * -2 if there is no section name in the key.
  *
  * store_key - pointer to char* which will hold a copy of the key with
- *             lowercase section and variable name
+ *             lowercase section and variable name, can be NULL to skip
+ *             allocation when only validation is needed
  * baselen - pointer to size_t which will hold the length of the
  *           section + subsection part, can be NULL
+ * quiet - when non-zero, suppress error() reports on rejection
  */
-int git_config_parse_key(const char *key, char **store_key, size_t *baselen_)
+int git_config_parse_key(const char *key, char **store_key, size_t *baselen_,
+			 int quiet)
 {
 	size_t i, baselen;
 	int dot;
@@ -552,12 +555,14 @@ int git_config_parse_key(const char *key, char **store_key, size_t *baselen_)
 	 */
 
 	if (last_dot == NULL || last_dot == key) {
-		error(_("key does not contain a section: %s"), key);
+		if (!quiet)
+			error(_("key does not contain a section: %s"), key);
 		return -CONFIG_NO_SECTION_OR_NAME;
 	}
 
 	if (!last_dot[1]) {
-		error(_("key does not contain variable name: %s"), key);
+		if (!quiet)
+			error(_("key does not contain variable name: %s"), key);
 		return -CONFIG_NO_SECTION_OR_NAME;
 	}
 
@@ -568,7 +573,8 @@ int git_config_parse_key(const char *key, char **store_key, size_t *baselen_)
 	/*
 	 * Validate the key and while at it, lower case it for matching.
 	 */
-	*store_key = xmallocz(strlen(key));
+	if (store_key)
+		*store_key = xmallocz(strlen(key));
 
 	dot = 0;
 	for (i = 0; key[i]; i++) {
@@ -579,21 +585,25 @@ int git_config_parse_key(const char *key, char **store_key, size_t *baselen_)
 		if (!dot || i > baselen) {
 			if (!iskeychar(c) ||
 			    (i == baselen + 1 && !isalpha(c))) {
-				error(_("invalid key: %s"), key);
+				if (!quiet)
+					error(_("invalid key: %s"), key);
 				goto out_free_ret_1;
 			}
 			c = tolower(c);
 		} else if (c == '\n') {
-			error(_("invalid key (newline): %s"), key);
+			if (!quiet)
+				error(_("invalid key (newline): %s"), key);
 			goto out_free_ret_1;
 		}
-		(*store_key)[i] = c;
+		if (store_key)
+			(*store_key)[i] = c;
 	}
 
 	return 0;
 
 out_free_ret_1:
-	FREE_AND_NULL(*store_key);
+	if (store_key)
+		FREE_AND_NULL(*store_key);
 	return -CONFIG_INVALID_KEY;
 }
 
@@ -609,7 +619,7 @@ static int config_parse_pair(const char *key, const char *value,
 
 	if (!strlen(key))
 		return error(_("empty config key"));
-	if (git_config_parse_key(key, &canonical_name, NULL))
+	if (git_config_parse_key(key, &canonical_name, NULL, 0))
 		return -1;
 
 	ret = (fn(canonical_name, value, &ctx, data) < 0) ? -1 : 0;
@@ -1708,7 +1718,7 @@ static int configset_find_element(struct config_set *set, const char *key,
 	 * `key` may come from the user, so normalize it before using it
 	 * for querying entries from the hashmap.
 	 */
-	ret = git_config_parse_key(key, &normalized_key, NULL);
+	ret = git_config_parse_key(key, &normalized_key, NULL, 0);
 	if (ret)
 		return ret;
 
@@ -3001,7 +3011,7 @@ int repo_config_set_multivar_in_file_gently(struct repository *r,
 	validate_comment_string(comment);
 
 	/* parse-key returns negative; flip the sign to feed exit(3) */
-	ret = 0 - git_config_parse_key(key, &store.key, &store.baselen);
+	ret = 0 - git_config_parse_key(key, &store.key, &store.baselen, 0);
 	if (ret)
 		goto out_free;
 
diff --git a/config.h b/config.h
index bf47fb3afc..2c66d334c1 100644
--- a/config.h
+++ b/config.h
@@ -341,7 +341,7 @@ int repo_config_set_worktree_gently(struct repository *, const char *, const cha
  */
 void repo_config_set(struct repository *, const char *, const char *);
 
-int git_config_parse_key(const char *, char **, size_t *);
+int git_config_parse_key(const char *, char **, size_t *, int quiet);
 
 /*
  * The following macros specify flag bits that alter the behavior
diff --git a/submodule-config.c b/submodule-config.c
index a81897b4e0..a319956f7a 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -970,7 +970,7 @@ int print_config_from_gitmodules(struct repository *repo, const char *key)
 	int ret;
 	char *store_key;
 
-	ret = git_config_parse_key(key, &store_key, NULL);
+	ret = git_config_parse_key(key, &store_key, NULL, 0);
 	if (ret < 0)
 		return CONFIG_INVALID_KEY;
 
-- 
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