FirefoxBase.get_frame() (firefox_base.py ~line 5499) locates the iframe element correctly via self.ele(locator), then attempts to match it to a child browsing context by comparing ele.attr("src") against the context URL from browsingContext.getTree():
ele_src = ele.attr("src") or ""
for child in children:
child_url = child.get("url", "")
if ele_src and ele_src in child_url:
return FirefoxFrame(...)Root cause found: The iframe's src attribute and the browsing context URL are nearly identical, except the browsing context URL appends an explicit :443 (default HTTPS port), while the src attribute omits it. For example:
ele_src: https://example.com/path
child_url: https://example.com:443/path
Since a string "xxx.in" check against "...:443..." may fail depending on exact positions, or the port suffix causes a mismatch in how Firefox reports the context URL vs. the DOM src value, the get_frame(locator=...) returns None even though the iframe element is correctly found.
Steps to reproduce
Current workaround: Use get_frame(index=4) to bypass the URL matching logic.
Suggested fix: Normalize both URLs before comparison (strip default ports) to make the src-to-context matching more robust. Alternatively, use the element's sharedId to look up the corresponding browsing context directly via BiDi, which would avoid URL string matching entirely.
FirefoxBase.get_frame()(firefox_base.py ~line 5499) locates the iframe element correctly viaself.ele(locator), then attempts to match it to a child browsing context by comparingele.attr("src")against the context URL frombrowsingContext.getTree():Root cause found: The iframe's src attribute and the browsing context URL are nearly identical, except the browsing context URL appends an explicit :443 (default HTTPS port), while the src attribute omits it. For example:
ele_src: https://example.com/path
child_url: https://example.com:443/path
Since a string "xxx.in" check against "...:443..." may fail depending on exact positions, or the port suffix causes a mismatch in how Firefox reports the context URL vs. the DOM src value, the get_frame(locator=...) returns None even though the iframe element is correctly found.
Steps to reproduce
Current workaround: Use get_frame(index=4) to bypass the URL matching logic.
Suggested fix: Normalize both URLs before comparison (strip default ports) to make the src-to-context matching more robust. Alternatively, use the element's sharedId to look up the corresponding browsing context directly via BiDi, which would avoid URL string matching entirely.