From a6bd2c0897a626f4d6d7fb585324361019fb73cd Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Wed, 26 Jun 2024 22:25:08 +0200
Subject: [PATCH] LIBKML: fix writing a .kmz to cloud storage

Fixes #10313
---
 autotest/ogr/ogr_libkml.py                    | 11 +++++++++
 .../libkml/ogrlibkmldatasource.cpp            | 24 ++++++++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/autotest/ogr/ogr_libkml.py b/autotest/ogr/ogr_libkml.py
index 28608e370283..f92ba78c1822 100755
--- a/autotest/ogr/ogr_libkml.py
+++ b/autotest/ogr/ogr_libkml.py
@@ -455,6 +455,17 @@ def test_ogr_libkml_write_kmz_use_doc_off(tmp_vsimem):
     ogr_libkml_check_write(tmp_vsimem / "libkml_use_doc_off.kmz")
 
 
+def test_ogr_libkml_write_kmz_simulate_cloud(tmp_vsimem):
+    with gdal.config_option("CPL_VSIL_USE_TEMP_FILE_FOR_RANDOM_WRITE", "FORCED"):
+        ogr_libkml_write(tmp_vsimem / "test_ogr_libkml_write_kmz_simulate_cloud.kmz")
+
+    ogr_libkml_check_write(tmp_vsimem / "test_ogr_libkml_write_kmz_simulate_cloud.kmz")
+
+    with gdal.config_option("CPL_VSIL_USE_TEMP_FILE_FOR_RANDOM_WRITE", "FORCED"):
+        with pytest.raises(Exception):
+            ogr_libkml_write("/i_do/not/exist.kmz")
+
+
 ###############################################################################
 # Test reading attributes with XML content in them
 #
diff --git a/ogr/ogrsf_frmts/libkml/ogrlibkmldatasource.cpp b/ogr/ogrsf_frmts/libkml/ogrlibkmldatasource.cpp
index ac600fe32475..5cf1c16b394e 100644
--- a/ogr/ogrsf_frmts/libkml/ogrlibkmldatasource.cpp
+++ b/ogr/ogrsf_frmts/libkml/ogrlibkmldatasource.cpp
@@ -412,7 +412,16 @@ static KmlPtr OGRLIBKMLCreateOGCKml22(KmlFactory *poFactory,
 
 bool OGRLIBKMLDataSource::WriteKmz()
 {
-    void *hZIP = CPLCreateZip(m_pszName, nullptr);
+    std::string osTmpFilename;
+    if (!VSISupportsRandomWrite(m_pszName, false) ||
+        EQUAL(CPLGetConfigOption("CPL_VSIL_USE_TEMP_FILE_FOR_RANDOM_WRITE", ""),
+              "FORCED"))
+    {
+        osTmpFilename = CPLGenerateTempFilename(CPLGetBasename(m_pszName));
+    }
+
+    void *hZIP = CPLCreateZip(
+        osTmpFilename.empty() ? m_pszName : osTmpFilename.c_str(), nullptr);
 
     if (!hZIP)
     {
@@ -536,6 +545,19 @@ bool OGRLIBKMLDataSource::WriteKmz()
     }
 
     CPLCloseZip(hZIP);
+
+    if (!osTmpFilename.empty())
+    {
+        if (bRet)
+        {
+            bRet = CPLCopyFile(m_pszName, osTmpFilename.c_str()) == 0;
+            if (!bRet)
+                CPLError(CE_Failure, CPLE_FileIO,
+                         "Cannot copy temporary file to %s", m_pszName);
+        }
+        VSIUnlink(osTmpFilename.c_str());
+    }
+
     return bRet;
 }