Fix obscure crash with rsource and $srctree pointing to a symlink

Sourcing a file with an absolute path and using rsource in it triggered
a relpath() between the absolute path and $srctree. Since e.g.
symlink/../bar/ = bar/ is not guaranteed for symlinks, this could lead
to the rsource'd file not being found if $srctree pointed to a symlink.

Switch to a simpler, more textual method for stripping $srctree from
glob results, which should be robust against symlink shenanigans. This
also makes the code a bit easier to follow.

Discovered by Marc Herbert.

Piggyback some minor cleanup.

4 files changed, 6 insertions, 0 deletions

diff --git a/tests/sub/Kconfig_symlink_2 b/tests/sub/Kconfig_symlink_2
new file mode 100644
index 0000000..aeba985
--- /dev/null
+++ b/tests/sub/Kconfig_symlink_2
@@ -0,0 +1 @@
+rsource "Kconfig_symlink_3"
diff --git a/tests/sub/Kconfig_symlink_3 b/tests/sub/Kconfig_symlink_3
new file mode 100644
index 0000000..20b4e06
--- /dev/null
+++ b/tests/sub/Kconfig_symlink_3
@@ -0,0 +1,2 @@
+config FOUNDME
+    bool
diff --git a/tests/sub/sub/Kconfig_symlink_1 b/tests/sub/sub/Kconfig_symlink_1
new file mode 100644
index 0000000..bceec8b
--- /dev/null
+++ b/tests/sub/sub/Kconfig_symlink_1
@@ -0,0 +1,2 @@
+# Sources tests/sub/Kconfig_symlink_2, with an absolute path
+source "$(KCONFIG_SYMLINK_2)"
diff --git a/tests/symlink b/tests/symlink
new file mode 120000
index 0000000..565623e
--- /dev/null
+++ b/tests/symlink
@@ -0,0 +1 @@
+sub/sub
\ No newline at end of file