0001-godot-seek.patch

diff --git a/thirdparty/minizip/ioapi.c b/thirdparty/minizip/ioapi.c
index 782d32469a..2e393aca2d 100644
--- a/thirdparty/minizip/ioapi.c
+++ b/thirdparty/minizip/ioapi.c
@@ -75,9 +75,12 @@ void fill_zlib_filefunc64_32_def_from_filefunc32(zlib_filefunc64_32_def* p_filef
     p_filefunc64_32->zfile_func64.opaque = p_filefunc32->opaque;
     p_filefunc64_32->zseek32_file = p_filefunc32->zseek_file;
     p_filefunc64_32->ztell32_file = p_filefunc32->ztell_file;
+    p_filefunc64_32->zfile_func64.alloc_mem = p_filefunc32->alloc_mem;
+    p_filefunc64_32->zfile_func64.free_mem = p_filefunc32->free_mem;
 }
 
 
+#if 0
 
 static voidpf ZCALLBACK fopen_file_func(voidpf opaque, const char* filename, int mode) {
     FILE* file = NULL;
@@ -229,3 +232,5 @@ void fill_fopen64_filefunc(zlib_filefunc64_def* pzlib_filefunc_def) {
     pzlib_filefunc_def->zerror_file = ferror_file_func;
     pzlib_filefunc_def->opaque = NULL;
 }
+
+#endif
diff --git a/thirdparty/minizip/ioapi.h b/thirdparty/minizip/ioapi.h
index a2d2e6e60d..556dd8ad18 100644
--- a/thirdparty/minizip/ioapi.h
+++ b/thirdparty/minizip/ioapi.h
@@ -155,6 +155,8 @@ typedef struct zlib_filefunc_def_s
     close_file_func     zclose_file;
     testerror_file_func zerror_file;
     voidpf              opaque;
+    alloc_func          alloc_mem;
+    free_func           free_mem;
 } zlib_filefunc_def;
 
 typedef ZPOS64_T (ZCALLBACK *tell64_file_func)    (voidpf opaque, voidpf stream);
@@ -171,6 +173,8 @@ typedef struct zlib_filefunc64_def_s
     close_file_func     zclose_file;
     testerror_file_func zerror_file;
     voidpf              opaque;
+    alloc_func          alloc_mem;
+    free_func           free_mem;
 } zlib_filefunc64_def;
 
 void fill_fopen64_filefunc(zlib_filefunc64_def* pzlib_filefunc_def);
diff --git a/thirdparty/minizip/unzip.c b/thirdparty/minizip/unzip.c
index ea05b7d62a..7e8a6ac2d3 100644
--- a/thirdparty/minizip/unzip.c
+++ b/thirdparty/minizip/unzip.c
@@ -152,6 +152,7 @@ typedef struct
     uLong compression_method;   /* compression method (0==store) */
     ZPOS64_T byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
     int   raw;
+    int extra_size;
 } file_in_zip64_read_info_s;
 
 
@@ -513,9 +514,9 @@ local unzFile unzOpenInternal(const void *path,
     us.z_filefunc.zseek32_file = NULL;
     us.z_filefunc.ztell32_file = NULL;
     if (pzlib_filefunc64_32_def==NULL)
-        fill_fopen64_filefunc(&us.z_filefunc.zfile_func64);
-    else
-        us.z_filefunc = *pzlib_filefunc64_32_def;
+        //fill_fopen64_filefunc(&us.z_filefunc.zfile_func64);
+        return NULL; // standard i/o not supported
+    us.z_filefunc = *pzlib_filefunc64_32_def;
     us.is64bitOpenFunction = is64bitOpenFunction;
 
 
@@ -703,6 +704,15 @@ extern unzFile ZEXPORT unzOpen64(const void *path) {
     return unzOpenInternal(path, NULL, 1);
 }
 
+extern void* unzGetOpaque(unzFile file) {
+    unz64_s* s;
+    if (file==NULL)
+        return NULL;
+    s=(unz64_s*)file;
+
+    return s->z_filefunc.zfile_func64.opaque;
+}
+
 /*
   Close a ZipFile opened with unzOpen.
   If there is files inside the .Zip opened with unzOpenCurrentFile (see later),
@@ -905,10 +915,19 @@ local int unz64local_GetCurrentFileInfoInternal(unzFile file,
 
         if (lSeek!=0)
         {
-            if (ZSEEK64(s->z_filefunc, s->filestream,(ZPOS64_T)lSeek,ZLIB_FILEFUNC_SEEK_CUR)==0)
-                lSeek=0;
-            else
-                err=UNZ_ERRNO;
+            if (lSeek<0) {
+                // WORKAROUND for backwards seeking
+                ZPOS64_T pos = ZTELL64(s->z_filefunc, s->filestream);
+                if (ZSEEK64(s->z_filefunc, s->filestream,pos+(ZPOS64_T)lSeek,ZLIB_FILEFUNC_SEEK_SET)==0)
+                    lSeek=0;
+                else
+                    err=UNZ_ERRNO;
+            } else {
+                if (ZSEEK64(s->z_filefunc, s->filestream,(ZPOS64_T)lSeek,ZLIB_FILEFUNC_SEEK_CUR)==0)
+                    lSeek=0;
+                else
+                    err=UNZ_ERRNO;
+            }
         }
 
         while(acc < file_info.size_file_extra)
@@ -1446,8 +1465,8 @@ extern int ZEXPORT unzOpenCurrentFile3(unzFile file, int* method,
     }
     else if ((s->cur_file_info.compression_method==Z_DEFLATED) && (!raw))
     {
-      pfile_in_zip_read_info->stream.zalloc = (alloc_func)0;
-      pfile_in_zip_read_info->stream.zfree = (free_func)0;
+      pfile_in_zip_read_info->stream.zalloc = s->z_filefunc.zfile_func64.alloc_mem;
+      pfile_in_zip_read_info->stream.zfree = s->z_filefunc.zfile_func64.free_mem;
       pfile_in_zip_read_info->stream.opaque = (voidpf)0;
       pfile_in_zip_read_info->stream.next_in = 0;
       pfile_in_zip_read_info->stream.avail_in = 0;
@@ -1480,6 +1499,7 @@ extern int ZEXPORT unzOpenCurrentFile3(unzFile file, int* method,
               iSizeVar;
 
     pfile_in_zip_read_info->stream.avail_in = (uInt)0;
+    pfile_in_zip_read_info->extra_size = iSizeVar;
 
     s->pfile_in_zip_read = pfile_in_zip_read_info;
                 s->encrypted = 0;
@@ -1510,6 +1530,84 @@ extern int ZEXPORT unzOpenCurrentFile3(unzFile file, int* method,
     return UNZ_OK;
 }
 
+extern int ZEXPORT unzSeekCurrentFile(unzFile file, int pos) {
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+    if (pfile_in_zip_read_info->compression_method==Z_BZIP2ED) { // don't know how to support bzip
+        return UNZ_INTERNALERROR;
+    }
+
+    if ((pfile_in_zip_read_info->compression_method==0) || (pfile_in_zip_read_info->raw)) {
+
+        pfile_in_zip_read_info->rest_read_compressed =
+                s->cur_file_info.compressed_size - pos;
+        pfile_in_zip_read_info->rest_read_uncompressed =
+                s->cur_file_info.uncompressed_size - pos;
+
+        pfile_in_zip_read_info->pos_in_zipfile =
+                s->cur_file_info_internal.offset_curfile + SIZEZIPLOCALHEADER +
+                        pfile_in_zip_read_info->extra_size + pos;
+
+        pfile_in_zip_read_info->stream.avail_in = (uInt)0;
+        pfile_in_zip_read_info->stream.total_out = pos;
+        pfile_in_zip_read_info->total_out_64 = pos;
+
+        return ZSEEK64(pfile_in_zip_read_info->z_filefunc,
+                       pfile_in_zip_read_info->filestream,
+                       pfile_in_zip_read_info->byte_before_the_zipfile + pfile_in_zip_read_info->pos_in_zipfile,
+                       ZLIB_FILEFUNC_SEEK_SET);
+
+    } else { // gzip
+
+        if (pos < pfile_in_zip_read_info->stream.total_out) { // negative seek, rewind
+
+            pfile_in_zip_read_info->rest_read_compressed =
+                    s->cur_file_info.compressed_size ;
+            pfile_in_zip_read_info->rest_read_uncompressed =
+                    s->cur_file_info.uncompressed_size ;
+
+            pfile_in_zip_read_info->pos_in_zipfile =
+                    s->cur_file_info_internal.offset_curfile + SIZEZIPLOCALHEADER +
+                            pfile_in_zip_read_info->extra_size;
+
+            (void)inflateReset(&pfile_in_zip_read_info->stream);
+
+            pfile_in_zip_read_info->stream.avail_in = (uInt)0;
+            pfile_in_zip_read_info->stream.total_out = 0;
+            pfile_in_zip_read_info->total_out_64 = 0;
+            pfile_in_zip_read_info->stream.next_in = 0;
+        }
+
+        // not sure where to read, so read on the stack
+        {
+            char buf[512];
+            int to_read = pos - pfile_in_zip_read_info->stream.total_out;
+            while (to_read) {
+
+                int len = to_read > sizeof(buf)?sizeof(buf):to_read;
+                int read = unzReadCurrentFile(file, buf, len);
+                if (read < 0) {
+                    return read;
+                }
+                to_read -= read;
+                if (read == UNZ_EOF) {
+                    return pos;
+                }
+            }
+        }
+    }
+
+    return pos;
+}
+
 extern int ZEXPORT unzOpenCurrentFile(unzFile file) {
     return unzOpenCurrentFile3(file, NULL, NULL, 0, NULL);
 }
diff --git a/thirdparty/minizip/unzip.h b/thirdparty/minizip/unzip.h
index 5cfc9c6274..37ff29b22a 100644
--- a/thirdparty/minizip/unzip.h
+++ b/thirdparty/minizip/unzip.h
@@ -202,6 +202,8 @@ extern int ZEXPORT unzClose(unzFile file);
     these files MUST be closed with unzCloseCurrentFile before call unzClose.
   return UNZ_OK if there is no problem. */
 
+extern void* unzGetOpaque(unzFile file);
+
 extern int ZEXPORT unzGetGlobalInfo(unzFile file,
                                     unz_global_info *pglobal_info);
 
@@ -390,6 +392,11 @@ extern int ZEXPORT unzReadCurrentFile(unzFile file,
     (UNZ_ERRNO for IO error, or zLib error for uncompress error)
 */
 
+extern int ZEXPORT unzSeekCurrentFile(unzFile file, int pos);
+/*
+  Seek to position in uncompressed data
+*/
+
 extern z_off_t ZEXPORT unztell(unzFile file);
 
 extern ZPOS64_T ZEXPORT unztell64(unzFile file);
diff --git a/thirdparty/minizip/zip.c b/thirdparty/minizip/zip.c
index 60bdffac34..078a0a82ec 100644
--- a/thirdparty/minizip/zip.c
+++ b/thirdparty/minizip/zip.c
@@ -820,9 +820,9 @@ extern zipFile ZEXPORT zipOpen3(const void *pathname, int append, zipcharpc* glo
 
     ziinit.z_filefunc.zseek32_file = NULL;
     ziinit.z_filefunc.ztell32_file = NULL;
-    if (pzlib_filefunc64_32_def==NULL)
-        fill_fopen64_filefunc(&ziinit.z_filefunc.zfile_func64);
-    else
+    if (pzlib_filefunc64_32_def==NULL) {
+        //fill_fopen64_filefunc(&ziinit.z_filefunc.zfile_func64);
+    } else
         ziinit.z_filefunc = *pzlib_filefunc64_32_def;
 
     ziinit.filestream = ZOPEN64(ziinit.z_filefunc,
@@ -1182,8 +1182,8 @@ extern int ZEXPORT zipOpenNewFileInZip4_64(zipFile file, const char* filename, c
     {
         if(zi->ci.method == Z_DEFLATED)
         {
-          zi->ci.stream.zalloc = (alloc_func)0;
-          zi->ci.stream.zfree = (free_func)0;
+          zi->ci.stream.zalloc = zi->z_filefunc.zfile_func64.alloc_mem;
+          zi->ci.stream.zfree = zi->z_filefunc.zfile_func64.free_mem;
           zi->ci.stream.opaque = (voidpf)0;
 
           if (windowBits>0)