[PATCH] config: add show_err flag to git_config_parse_key()

`git_config_parse_key()` is used to sanitize the input key.
Some callers of the function like `git_config_set_multivar_in_file()`
get the pre-sanitized key directly from the user so it becomes
necessary to raise an error specifying what went wrong when the entered
key is defective.

Other callers like `configset_find_element()` get their keys from
the git itself so a return value signifying error would be enough.
The error output shown to the user is useless and confusing in this
case so add a show_err flag to suppress errors in such cases.

Signed-off-by: Tanay Abhra <redacted>
---

Hi,

You were right, one of the functions was calling git_config_parse_key()
which was leaking errors to the console. git_config_parse_key() was
meant for sanitizing user provided keys only but it was being used
internally in a place where only a return value would be enough.

Thanks for bringing this to our attention.

Cheers,
Tanay Abhra.

 builtin/config.c |  2 +-
 cache.h          |  2 +-
 config.c         | 19 ++++++++++++-------
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/builtin/config.c b/builtin/config.c
index 8cc2604..51635dc 100644
--- a/builtin/config.c
+++ b/builtin/config.c

@@ -200,7 +200,7 @@ static int get_value(const char *key_, const char *regex_)
             goto free_strings;
         }
     } else {
-        if (git_config_parse_key(key_, &key, NULL)) {
+        if (git_config_parse_key(key_, &key, NULL, 1)) {
             ret = CONFIG_INVALID_KEY;
             goto free_strings;
         }

diff --git a/cache.h b/cache.h
index 99ed096..8129590 100644
--- a/cache.h
+++ b/cache.h

@@ -1362,7 +1362,7 @@ extern int git_config_string(const char **,

const char *, const char *);
 extern int git_config_pathname(const char **, const char *, const char *);
 extern int git_config_set_in_file(const char *, const char *, const char *);
 extern int git_config_set(const char *, const char *);
-extern int git_config_parse_key(const char *, char **, int *);
+extern int git_config_parse_key(const char *, char **, int *, int);
 extern int git_config_set_multivar(const char *, const char *, const
char *, int);
 extern int git_config_set_multivar_in_file(const char *, const char
*, const char *, const char *, int);
 extern int git_config_rename_section(const char *, const char *);

diff --git a/config.c b/config.c
index 15a2983..eb9058c 100644
--- a/config.c
+++ b/config.c

@@ -1299,7 +1299,7 @@ static struct config_set_element

*configset_find_element(struct config_set *cs,
      * `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 NULL;

@@ -1832,8 +1832,9 @@ int git_config_set(const char *key, const char *value)
  *             lowercase section and variable name
  * baselen - pointer to int which will hold the length of the
  *           section + subsection part, can be NULL
+ * show_err - toggle whether the function raises an error on a defective key
  */
-int git_config_parse_key(const char *key, char **store_key, int *baselen_)
+int git_config_parse_key(const char *key, char **store_key, int

*baselen_, int show_err)
 {
     int i, dot, baselen;
     const char *last_dot = strrchr(key, '.');

@@ -1844,12 +1845,14 @@ int git_config_parse_key(const char *key, char

**store_key, int *baselen_)
      */

     if (last_dot == NULL || last_dot == key) {
-        error("key does not contain a section: %s", key);
+        if (show_err)
+            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 (show_err)
+            error("key does not contain variable name: %s", key);
         return -CONFIG_NO_SECTION_OR_NAME;
     }

@@ -1871,12 +1874,14 @@ int git_config_parse_key(const char *key, char

**store_key, int *baselen_)
         if (!dot || i > baselen) {
             if (!iskeychar(c) ||
                 (i == baselen + 1 && !isalpha(c))) {
-                error("invalid key: %s", key);
+                if (show_err)
+                    error("invalid key: %s", key);
                 goto out_free_ret_1;
             }
             c = tolower(c);
         } else if (c == '\n') {
-            error("invalid key (newline): %s", key);
+            if (show_err)
+                error("invalid key (newline): %s", key);
             goto out_free_ret_1;
         }
         (*store_key)[i] = c;

@@ -1926,7 +1931,7 @@ int git_config_set_multivar_in_file(const char

*config_filename,
     char *filename_buf = NULL;

     /* 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, 1);
     if (ret)
         goto out_free;

-- 
1.9.0.GIT