Fix GH-19681 PHP_EXPAND_PATH broken with bash 5.3.0

[remicollet]

With bash 5.3.0 cd "" (empty path) now outputs an error sh: cd: null directory and fails

[remicollet]

For 8.4+, mostly the same (code has diverged)

--- ./build/php.m4	2025-09-04 09:04:47.251889450 +0200
+++ ./build/php.m4.ok	2025-09-04 09:05:04.550323046 +0200
@@ -63,7 +63,11 @@
     changequote({,})
     ep_dir=$(echo $1|$SED 's%/*[^/][^/]*/*$%%')
     changequote([,])
-    ep_realdir=$(cd "$ep_dir" && pwd)
+    if test -z $ep_dir ; then
+      ep_realdir=$(pwd)
+    else
+      ep_realdir=$(cd "$ep_dir" && pwd)
+    fi
     $2="$ep_realdir"/$(basename "$1")
   fi
 ])

[petk]

Sounds find with me. Nice catch. Recent POSIX seemed to changed this behavior so this sounds correct, yes.

[remicollet]

Merged as 98d2b92 and abbf840

[remicollet]

For 8.4, see 3a88977