Subject: [PATCH v3 0/4] enhance string-list API to fix sign compare warnings

From: shejialuo <[email-masked]>
Date: Mon, 6 Oct 2025 14:28:42 +0800

Hi All:

This is a small PATCH to enhance string-list API
"string_list_find_insert_index" which has introduced sign compare
warnings.

---

Changes since v2:

1. Enhance [PATCH v2 2/4] commit message to express the motivation is
   avoid overflow.
2. Add comments for `string_list_find_insert_index` function.

---

Changes since v1:

1. Create a new commit which aims at using `bool` for "exact_match"
   parameter.
2. Rebase the [PATCH 1/4] and [PATCH 2/4] into a single [PATCH v2 2/4]
   commit to avoid confusing the user with the motivation of the
   original commit [PATCH 1/4].
3. Enhance the comimt message of [PATCH 2/4] to improve the motivation.
4. Update "i-- > 0" to "i--" for [PATCH 3/4]

Thanks,
Jialuo

shejialuo (4):
  string-list: use bool instead of int for "exact_match"
  string-list: replace negative index encoding with "exact_match"
    parameter
  string-list: change "string_list_find_insert_index" return type to
    "size_t"
  refs: enable sign compare warnings check

 add-interactive.c |  7 ++++---
 mailmap.c         | 10 ++++------
 refs.c            | 13 ++++---------
 string-list.c     | 29 ++++++++++++++---------------
 string-list.h     | 12 +++++++++---
 5 files changed, 35 insertions(+), 36 deletions(-)

Range-diff against v2:
1:  c3786fa386 = 1:  bdcac9b5fa string-list: use bool instead of int for "exact_match"
2:  7ac8fd69c0 ! 2:  0d6d09c8b0 string-list: replace negative index encoding with "exact_match" parameter
    @@ Metadata
      ## Commit message ##
         string-list: replace negative index encoding with "exact_match" parameter
     
    -    We would return negative index to indicate exact match by converting the
    -    original positive index to be "-1 - index" in
    -    "string_list_find_insert_index", which requires callers to decode this
    -    information. This approach has several limitations:
    +    The "string_list_find_insert_index()" function is used to determine
    +    the correct insertion index for a new string within the string list.
    +    The function also doubles up to convey if the string is already
    +    existing in the list, this is done by returning a negative index
    +    "-1 -index". Users are expected to decode this information. This
    +    approach has several limitations:
     
    -    1. It prevents us from using the full range of size_t, which is
    -       necessary for large string list.
    -    2. Using int for indices while other parts of the codebase use size_t
    -       creates signed comparison warnings when these values are compared.
    +    1. It requires the callers to look into the detail of the function to
    +       understand how to decode the negative index encoding.
    +    2. Using int for indices can cause overflow issues when dealing with
    +       large string lists.
     
         To address these limitations, change the function to return size_t for
         the index value and use a separate bool parameter to indicate whether
3:  1cf914fab5 ! 3:  9bfe17ab19 string-list: change "string_list_find_insert_index" return type to "size_t"
    @@ string-list.h: void string_list_remove_empty_items(struct string_list *list, int
      bool string_list_has_string(const struct string_list *list, const char *string);
     -int string_list_find_insert_index(const struct string_list *list, const char *string,
     -				  bool *exact_match);
    ++
    ++/**
    ++ * Find the index at which a new element should be inserted into the
    ++ * string_list to maintain sorted order. If exact_match is not NULL,
    ++ * it will be set to true if the string already exists in the list.
    ++ */
     +size_t string_list_find_insert_index(const struct string_list *list, const char *string,
     +				     bool *exact_match);
      
4:  8a445549dd = 4:  2a602954f2 refs: enable sign compare warnings check
-- 
2.51.0