Shawn O. PearceJunio and I both noticed that the new builtin-fetch was segfaulting immediately on http/https/ftp style URLs (those that went through libcurl and the commit walker). Although the builtin-fetch changes in this area were really just minor refactorings there was one major change made: we invoked http_init(), http_cleanup() then http_init() again in the same process.
When we call curl_easy_cleanup() on each active_request_slot we are telling libcurl we did not want that buffer to be used again. Unfortunately we did not also deallocate the active_request_slot itself nor did we NULL out active_queue_head. This lead us to attempt to reuse these cleaned up libcurl handles when we later tried to invoke http_init() a second time to reactivate the curl library. The next file get operation then immediately segfaulted on most versions of libcurl.
Properly freeing our own buffers and clearing the list causes us to reinitialize the curl buffers again if/when we need to use libcurl from within this same process.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org> --- http.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-)
Show changes to http.c +5 −2
diff --git a/http.c b/http.c index a95483b..87ebf7b 100644 --- a/http.c +++ b/http.c @@ -276,6 +276,7 @@ void http_cleanup(void) #endif while (slot != NULL) { + struct active_request_slot *next = slot->next; #ifdef USE_CURL_MULTI if (slot->in_use) { curl_easy_getinfo(slot->curl, @@ -287,8 +288,10 @@ void http_cleanup(void) #endif if (slot->curl != NULL) curl_easy_cleanup(slot->curl); - slot = slot->next; + free(slot); + slot = next; } + active_queue_head = NULL; #ifndef NO_CURL_EASY_DUPHANDLE curl_easy_cleanup(curl_default); @@ -300,7 +303,7 @@ void http_cleanup(void) curl_global_cleanup(); curl_slist_free_all(pragma_header); - pragma_header = NULL; + pragma_header = NULL; } struct active_request_slot *get_active_slot(void)
-- 1.5.3.1.84.gaf82-dirty