From a6300c3b29f96f0913a788287ae88524c5db4db7 Mon Sep 17 00:00:00 2001
From: Nathan Moin Vaziri <nathan@nathanm.com>
Date: Sun, 26 Apr 2026 18:47:40 -0700
Subject: [PATCH] compat: add unzGetCurrentFileZStreamPos64 (#848)

Returns the absolute offset where the current entry's compressed
data begins, matching the original minizip API used by chromium and
other consumers. The position is already tracked internally via
entry_pos for STORE-method seek support, so this just exposes it.
---
 compat/unzip.c | 7 +++++++
 compat/unzip.h | 1 +
 2 files changed, 8 insertions(+)

diff --git a/compat/unzip.c b/compat/unzip.c
index 3fa2e40..27bc670 100644
--- a/compat/unzip.c
+++ b/compat/unzip.c
@@ -629,6 +629,13 @@ int unzSetOffset64(unzFile file, int64_t pos) {
     return (int)mz_zip_goto_entry(compat->handle, pos);
 }
 
+uint64_t unzGetCurrentFileZStreamPos64(unzFile file) {
+    mz_unzip_compat *compat = (mz_unzip_compat *)file;
+    if (!compat || mz_zip_entry_is_open(compat->handle) != MZ_OK)
+        return 0;
+    return (uint64_t)compat->entry_pos;
+}
+
 int unzGetLocalExtrafield(unzFile file, void *buf, unsigned int len) {
     mz_unzip_compat *compat = (mz_unzip_compat *)file;
     mz_zip_file *file_info = NULL;
diff --git a/compat/unzip.h b/compat/unzip.h
index c4b707c..28548ab 100644
--- a/compat/unzip.h
+++ b/compat/unzip.h
@@ -217,6 +217,7 @@ ZEXPORT int64_t unzGetOffset64(unzFile file);
 ZEXPORT unsigned long unzGetOffset(unzFile file);
 ZEXPORT int unzSetOffset64(unzFile file, int64_t pos);
 ZEXPORT int unzSetOffset(unzFile file, unsigned long pos);
+ZEXPORT uint64_t unzGetCurrentFileZStreamPos64(unzFile file);
 ZEXPORT int32_t unztell(unzFile file);
 ZEXPORT uint64_t unztell64(unzFile file);
 ZEXPORT int unzeof(unzFile file);