Summary

search_issues().totalCount incorrectly returns 0 instead of the actual count from GitHub API responses when GitHub includes deprecation notices in Link headers.

Environment

• PyGithub Version: 2.8.1 (also affects 1.55 and likely all versions)
• Python Version: 3.9.12
• GitHub API: Enterprise GitHub (also affects github.com)

Problem Description

Since GitHub started including deprecation notices in Link headers (around early September 2025), PyGithub's search_issues() method incorrectly returns totalCount = 0 even when results exist.

Expected Behavior

issues = gh.search_issues("commit:EXAMPLE_COMMIT_SHA")
print(issues.totalCount)  # Should print: 1

Actual Behavior

issues = gh.search_issues("commit:EXAMPLE_COMMIT_SHA")
print(issues.totalCount)  # Actually prints: 0

Root Cause Analysis

File: github/PaginatedList.py, lines 152-165

The bug occurs in the totalCount property getter:

if "link" not in headers:  # Line 152 - ISSUE HERE
    # This path would correctly use data["total_count"]
    if data and "total_count" in data:
        self.__totalCount = data["total_count"]  # Would work correctly
else:
    # Takes this path due to deprecation Link header
    links = self.__parseLinkHeader(headers)
    lastUrl = links.get("last")  # Returns None (no pagination links)
    if lastUrl:
        self.__totalCount = int(parse_qs(lastUrl)["page"][0])
    else:
        self.__totalCount = 0  # BUG: Sets to 0 instead of using JSON total_count

The Issue: GitHub now includes deprecation notices in Link headers:

Link: <https://github.blog/changelog/2025-03-06-github-issues-projects-api-support-for-issues-advanced-search-and-more/>; rel="deprecation"; type="text/html"

PyGithub incorrectly assumes any Link header means pagination exists, but deprecation notices are not pagination links.

Reproduction Steps

1. Make any search that returns results:

   curl -H "Authorization: token YOUR_TOKEN" \
        "https://api.github.com/search/issues?q=commit:EXAMPLE_COMMIT_SHA"

   Returns: {"total_count": 1, "items": [...]}

2. Use PyGithub:

   import github
   from github import Auth
   
   auth = Auth.Token("YOUR_TOKEN")
   gh = github.Github(auth=auth)
   issues = gh.search_issues("commit:EXAMPLE_COMMIT_SHA")
   print(f"totalCount: {issues.totalCount}")  # Prints 0 instead of 1

Evidence

HTTP Response (captured with debugging):

{
  "total_count": 1,
  "incomplete_results": false,
  "items": [{"number": 12345, "title": "Example PR", ...}]
}

Response Headers:

Link: <https://github.blog/changelog/2025-03-06-github-issues-projects-api-support-for-issues-advanced-search-and-more/>; rel="deprecation"; type="text/html"

Parsed Links: {"deprecation": "https://github.blog/changelog/..."}
Result: No "last" link found → totalCount = 0

Proposed Fix

Change line 152 in PaginatedList.py from:

if "link" not in headers:

To:

if "link" not in headers or not self.__hasPaginationLinks(headers):

Where __hasPaginationLinks() checks for pagination-specific rel values ("next", "prev", "last", "first"), ignoring other Link types like deprecation notices.

Alternative implementation:

def __hasPaginationLinks(self, headers):
    """Check if Link header contains pagination links, not just deprecation notices"""
    if "link" not in headers:
        return False

    links = self.__parseLinkHeader(headers)
    pagination_rels = {"next", "prev", "last", "first"}
    return any(rel in pagination_rels for rel in links.keys())

Impact

This bug affects:

• All search operations (search_issues, search_repositories, search_users, etc.)
• Any application relying on search result counts
• Pagination logic when GitHub includes deprecation notices

Additional Context: This issue started appearing around early September 2025 when GitHub began including deprecation notices in API responses, breaking existing PyGithub installations that were working fine before.