Patch-Source: https://github.com/kjdev/php-ext-zstd/pull/110
Report success from the compress.zstd:// stream close handlers.

Both close handlers returned EOF unconditionally. Since PHP 8.6.0RC1
(php/php-src@c07cc8502c0, bug #60110) fclose(), file_put_contents() and
copy() propagate a non-zero close result as false, so every write through
the wrapper was reported as a failure.

diff --git a/tests/streams_10.phpt b/tests/streams_10.phpt
new file mode 100644
index 0000000..05d32c1
--- /dev/null
+++ b/tests/streams_10.phpt
@@ -0,0 +1,48 @@
+--TEST--
+compress.zstd streams report a successful close
+--FILE--
+<?php
+$file = dirname(__FILE__) . '/streams_10.out';
+$plain = dirname(__FILE__) . '/streams_10.txt';
+
+// As of PHP 8.6, fclose(), file_put_contents() and copy() return false when
+// closing the stream fails, so the close handler has to report success.
+$data = str_repeat('abcd', 1024);
+
+echo "Compress\n";
+
+$fp = fopen('compress.zstd://' . $file, 'w');
+var_dump($fp !== false);
+var_dump(fwrite($fp, $data) === strlen($data));
+var_dump(fclose($fp));
+
+echo "Decompress\n";
+
+$fp = fopen('compress.zstd://' . $file, 'r');
+var_dump($fp !== false);
+var_dump(stream_get_contents($fp) === $data);
+var_dump(fclose($fp));
+
+echo "Copy\n";
+
+file_put_contents($plain, $data);
+var_dump(copy($plain, 'compress.zstd://' . $file));
+var_dump(file_get_contents('compress.zstd://' . $file) === $data);
+
+@unlink($file);
+@unlink($plain);
+?>
+===DONE===
+--EXPECT--
+Compress
+bool(true)
+bool(true)
+bool(true)
+Decompress
+bool(true)
+bool(true)
+bool(true)
+Copy
+bool(true)
+bool(true)
+===DONE===
diff --git a/zstd.c b/zstd.c
index f0891e0..3c6f0fd 100644
--- a/zstd.c
+++ b/zstd.c
@@ -841,9 +841,13 @@ static int php_zstd_decomp_close(php_stream *stream, int close_handle)
         return EOF;
     }
 
+    int ret = 0;
+
     if (close_handle) {
         if (self->stream) {
-            php_stream_close(self->stream);
+            if (php_stream_close(self->stream)) {
+                ret = EOF;
+            }
             self->stream = NULL;
         }
     }
@@ -854,7 +858,7 @@ static int php_zstd_decomp_close(php_stream *stream, int close_handle)
     efree(self);
     stream->abstract = NULL;
 
-    return EOF;
+    return ret;
 }
 
 static int php_zstd_comp_flush_or_end(php_zstd_stream_data *self, int end)
@@ -872,9 +876,15 @@ static int php_zstd_comp_flush_or_end(php_zstd_stream_data *self, int end)
         if (ZSTD_isError(res)) {
             ZSTD_WARNING("zstd: %s", ZSTD_getErrorName(res));
             ret = EOF;
+            break;
+        }
+        if (self->ctx.output.pos
+            && (size_t) php_stream_write(self->stream, self->ctx.output.dst,
+                                         self->ctx.output.pos)
+               != self->ctx.output.pos) {
+            ret = EOF;
+            break;
         }
-        php_stream_write(self->stream,
-                         self->ctx.output.dst, self->ctx.output.pos);
     } while (res > 0);
 
     return ret;
@@ -897,11 +907,13 @@ static int php_zstd_comp_close(php_stream *stream, int close_handle)
         return EOF;
     }
 
-    php_zstd_comp_flush_or_end(self, 1);
+    int ret = php_zstd_comp_flush_or_end(self, 1);
 
     if (close_handle) {
         if (self->stream) {
-            php_stream_close(self->stream);
+            if (php_stream_close(self->stream)) {
+                ret = EOF;
+            }
             self->stream = NULL;
         }
     }
@@ -911,7 +923,7 @@ static int php_zstd_comp_close(php_stream *stream, int close_handle)
     efree(self);
     stream->abstract = NULL;
 
-    return EOF;
+    return ret;
 }
 
 
@@ -997,8 +1009,14 @@ php_zstd_comp_write(php_stream *stream, const char *buf, size_t count)
             return -1;
 #endif
         }
-        php_stream_write(self->stream,
-                         self->ctx.output.dst, self->ctx.output.pos);
+        if (self->ctx.output.pos
+            && (size_t) php_stream_write(self->stream, self->ctx.output.dst,
+                                         self->ctx.output.pos)
+               != self->ctx.output.pos) {
+#if PHP_VERSION_ID >= 70400
+            return -1;
+#endif
+        }
 
     } while (res > 0);