Test and document symlink loop

doc_src/cmds/path.rst

@@ -277,7 +277,7 @@ Examples
 
 ``path resolve`` returns the normalized, physical and absolute versions of all paths. That means it resolves symlinks and does what ``path normalize`` does: it squashes duplicate "/" (except for two leading "//"), collapses "../" with earlier components and removes "." components. Then it turns that path into the absolute path starting from the filesystem root "/".
 
-It is similar to ``realpath``, as it creates the "real", canonical version of the path. However, for nonexistent paths it will resolve as far as it can and normalize the nonexistent part.
+It is similar to ``realpath``, as it creates the "real", canonical version of the path. However, for paths that can't be resolved, e.g. if they don't exist or form a symlink loop, it will resolve as far as it can and normalize the rest.
 
 It returns 0 if any normalization or resolution was done, i.e. any given path wasn't in canonical form.
 

tests/checks/path.fish

@@ -184,3 +184,17 @@ path sort --unique --what=basename {def,abc}/{456,123,789} def/{abc,def,0} abc/{
 # CHECK: abc/foo
 
 
+
+# Symlink loop.
+# It goes brrr.
+ln -s target link
+ln -s link target
+
+test (path resolve target) = (pwd -P)/target
+and echo target resolves to target
+# CHECK: target resolves to target
+
+test (path resolve link) = (pwd -P)/link
+and echo link resolves to link
+# CHECK: link resolves to link
+