From: Vaidas Pilkauskas via GitGitGadget Date: Wed, 18 Feb 2026 14:09:03 GMT Subject: [PATCH v4 0/5] http: add support for HTTP 429 rate limit retries Message-ID: In-Reply-To: Changes since v3: * Clean up of all strbuf_attach() call sites * Add strbuf_attach() contract enforcement via BUG() Changes since v2: * New preparatory patch: Introduced show_http_message_fatal() helper function to reduce code duplication in remote-curl.c (suggested by Taylor Blau) * Removed specific HTTP_RATE_LIMITED error handling from http-push.c and http-walker.c for the obsolete "dumb" protocol, allowing generic error handling to take over (suggested by Jeff King) * Added support for CURLINFO_RETRY_AFTER on curl >= 7.66.0, falling back to manual header parsing on older versions * Simplified retry/delay architecture: replaced complex non-blocking "delayed slot" mechanism with simple blocking sleep() call in the retry loop, removing ~66 lines of timing logic (suggested by Jeff King) * Fixed Retry-After: 0 handling to allow immediate retry as specified by RFC 9110 * Changed http.retryAfter default from -1 to 0, so Git will retry immediately when encountering HTTP 429 without a Retry-After header, rather than failing with a configuration error * Improved error messages: shortened to be more concise * Fixed coding style issues: removed unnecessary curly braces, changed x == 0 to !x (per CodingGuidelines) * Improved test portability: replaced non-portable date(1) commands with test-tool date, added nanosecond-precision timing with getnanos, replaced cut(1) with POSIX shell parameter expansion * Split out strbuf.c bugfix into separate preparatory patch (the strbuf_reencode alloc size fix is unrelated to HTTP 429 support) * Squashed separate trace2 logging patch into main HTTP 429 retry support commit * Kept header_is_last_match assignment for Retry-After to prevent incorrect handling of HTTP header continuation lines The implementation includes: 1. A bug fix in strbuf_reencode() that corrects the allocation size passed to strbuf_attach(), passing len+1 instead of len so that the existing buffer is reused rather than immediately reallocated. 2. A cleanup of all strbuf_attach() call sites that were passing alloc == len, leaving no room for the NUL terminator. Sites with a known-NUL-terminated buffer now pass len+1; sites where the source buffer has no trailing NUL (ll_merge output) are converted to use strbuf_add() instead. 3. A hardening of strbuf_attach() itself: the internal strbuf_grow() that silently papered over incorrect alloc values is replaced with an explicit BUG() check, enforcing the documented contract that alloc must be greater than len. 4. A new show_http_message_fatal() helper in remote-curl.c that combines the repeated pattern of show_http_message() followed by die() into a single NORETURN function, reducing boilerplate at existing call sites and providing a clean hook for the retry logic. 5. The main feature: HTTP 429 retry logic with support for the Retry-After header (both delay-seconds and HTTP-date formats), configurable via http.maxRetries, http.retryAfter, and http.maxRetryTime options. If any computed delay exceeds maxRetryTime the request fails immediately with a clear diagnostic rather than capping and retrying silently. Vaidas Pilkauskas (5): strbuf: pass correct alloc to strbuf_attach() in strbuf_reencode() strbuf_attach: fix all call sites to pass correct alloc strbuf: replace strbuf_grow() in strbuf_attach() with BUG() check remote-curl: introduce show_http_message_fatal() helper http: add support for HTTP 429 rate limit retries Documentation/config/http.adoc | 23 +++ apply.c | 3 +- builtin/am.c | 2 +- builtin/fast-import.c | 2 +- git-curl-compat.h | 8 + http.c | 190 +++++++++++++++++++++-- http.h | 2 + mailinfo.c | 2 +- refs/files-backend.c | 2 +- remote-curl.c | 49 +++--- rerere.c | 3 +- strbuf.c | 5 +- t/lib-httpd.sh | 1 + t/lib-httpd/apache.conf | 8 + t/lib-httpd/http-429.sh | 98 ++++++++++++ t/meson.build | 1 + t/t5584-http-429-retry.sh | 266 +++++++++++++++++++++++++++++++++ trailer.c | 2 +- 18 files changed, 629 insertions(+), 38 deletions(-) create mode 100644 t/lib-httpd/http-429.sh create mode 100755 t/t5584-http-429-retry.sh base-commit: 73fd77805fc6406f31c36212846d9e2541d19321 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2008%2Fvaidas-shopify%2Fretry-after-v4 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2008/vaidas-shopify/retry-after-v4 Pull-Request: https://github.com/gitgitgadget/git/pull/2008 Range-diff vs v3: 1: 821043c664 ! 1: a3386f5b56 strbuf: fix incorrect alloc size in strbuf_reencode() @@ Metadata Author: Vaidas Pilkauskas ## Commit message ## - strbuf: fix incorrect alloc size in strbuf_reencode() + strbuf: pass correct alloc to strbuf_attach() in strbuf_reencode() - The strbuf_reencode() function incorrectly passes the string length - as the allocation size to strbuf_attach(), when it should pass - length + 1 to account for the null terminator. + reencode_string_len() allocates len+1 bytes (including the NUL) and + returns the string length in len. strbuf_reencode() was calling + strbuf_attach(sb, out, len, len), so alloc was one byte too small. - The reencode_string_len() function allocates len + 1 bytes (including - the null terminator) and returns the string length (excluding the null - terminator) via the len parameter. However, strbuf_reencode() then - calls strbuf_attach() with this length value as both the len and alloc - parameters: - - strbuf_attach(sb, out, len, len); - - This is incorrect because strbuf_attach()'s alloc parameter should - reflect the actual allocated buffer size, which includes space for the - null terminator. This could lead to incorrect memory management in code - that relies on sb->alloc being accurate. - - Fix by passing len + 1 as the alloc parameter: - - strbuf_attach(sb, out, len, len + 1); + strbuf_attach() then calls strbuf_grow(sb, 0). With alloc < len+1, + ALLOC_GROW always reallocates, so we reallocated immediately after + attach even when the strbuf was not extended further. Pass len+1 as + the alloc argument so the existing buffer is reused and the + reallocation is avoided. Signed-off-by: Vaidas Pilkauskas -: ---------- > 2: f48b1f07c4 strbuf_attach: fix all call sites to pass correct alloc -: ---------- > 3: 557fd77444 strbuf: replace strbuf_grow() in strbuf_attach() with BUG() check 2: 3653067f0e = 4: 3a39dc9e39 remote-curl: introduce show_http_message_fatal() helper 3: 3cece62a63 = 5: 5e0f4a56ef http: add support for HTTP 429 rate limit retries -- gitgitgadget