[Networking] Don't search for roots if we don't have CURLINFO_CAINFO.

`curl` versions before 7.84.0 don't have `CURLINFO_CAINFO`, so we
can't tell whether they've got an existing path for the CA roots
in that case.

We should disable the automatic search in that case, because it
would override the baked-in default.

rdar://123434144

Author: al45tair

CoreFoundation/CMakeLists.txt

@@ -411,6 +411,10 @@ if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
   if((NS_CURL_ASSUME_FEATURES_MISSING) OR (CURL_VERSION_STRING VERSION_LESS "7.30.0"))
     add_compile_definitions($<$<COMPILE_LANGUAGE:C>:NS_CURL_MISSING_MAX_HOST_CONNECTIONS>)
   endif()
+
+  if((NS_CURL_ASSUME_FEATURES_MISSING) OR (CURL_VERSION_STRING VERSION_LESS "7.84.0"))
+    add_compile_definitions($<$<COMPILE_LANGUAGE:C>:NS_CURL_MISSING_CURLINFO_CAINFO>)
+  endif()
 endif()
 
 add_framework(CFURLSessionInterface

CoreFoundation/URL.subproj/CFURLSessionInterface.c

@@ -586,7 +586,9 @@ CFURLSessionInfo const CFURLSessionInfoFTP_ENTRY_PATH = { CURLINFO_FTP_ENTRY_PAT
 CFURLSessionInfo const CFURLSessionInfoREDIRECT_URL = { CURLINFO_REDIRECT_URL };
 CFURLSessionInfo const CFURLSessionInfoPRIMARY_IP = { CURLINFO_PRIMARY_IP };
 CFURLSessionInfo const CFURLSessionInfoAPPCONNECT_TIME = { CURLINFO_APPCONNECT_TIME };
+#if !NS_CURL_MISSING_CURLINFO_CAINFO
 CFURLSessionInfo const CFURLSessionInfoCAINFO = { CURLINFO_CAINFO };
+#endif
 CFURLSessionInfo const CFURLSessionInfoCERTINFO = { CURLINFO_CERTINFO };
 CFURLSessionInfo const CFURLSessionInfoCONDITION_UNMET = { CURLINFO_CONDITION_UNMET };
 CFURLSessionInfo const CFURLSessionInfoRTSP_SESSION_ID = { CURLINFO_RTSP_SESSION_ID };

Sources/FoundationNetworking/CMakeLists.txt

@@ -15,6 +15,10 @@ if(NOT CMAKE_SYSTEM_NAME STREQUAL Darwin)
   if((NS_CURL_ASSUME_FEATURES_MISSING) OR (CURL_VERSION_STRING VERSION_LESS "7.30.0"))
     add_compile_definitions(NS_CURL_MISSING_MAX_HOST_CONNECTIONS)
   endif()
+
+  if((NS_CURL_ASSUME_FEATURES_MISSING) OR (CURL_VERSION_STRING VERSION_LESS "7.84.0"))
+    add_compile_definitions(NS_CURL_MISSING_CURLINFO_CAINFO)
+  endif()
 endif()
 
 add_library(FoundationNetworking

Sources/FoundationNetworking/URLSession/libcurl/EasyHandle.swift

@@ -209,6 +209,7 @@ extension _EasyHandle {
         }
 #endif
 
+#if !NS_CURL_MISSING_CURLINFO_CAINFO
 #if !os(Windows) && !os(macOS) && !os(iOS) && !os(watchOS) && !os(tvOS)
         // Check if there is a default path; if there is, it will already
         // be set, so leave things alone
@@ -240,7 +241,8 @@ extension _EasyHandle {
               return
           }
         }
-#endif
+#endif // !os(Windows) && !os(macOS) && !os(iOS) && !os(watchOS) && !os(tvOS)
+#endif // !NS_CURL_MISSING_CURLINFO_CAINFO
     }
 
     /// Set allowed protocols