fixes #22065; do not search path for relative imports (#22073)

* fixes #22065; do not search path for "./"

* simplify

* fixes

* fixes

* allow ".."

* cleanup

* add a test case

* slightly modify the import

* adds a changelog

changelogs/changelog_2_0_0.md

@@ -260,6 +260,8 @@
 
 - `strutils.split` and `strutils.rsplit` now forbid an empty separator.
 
+- Relative imports will not resolve to stdlib anymore, e.g. `import ./tables` now reports an error properly.
+
 ## Standard library additions and changes
 
 [//]: # "Changes:"

compiler/options.nim

@@ -910,6 +910,7 @@ proc findFile*(conf: ConfigRef; f: string; suppressStdlib = false): AbsoluteFile
 proc findModule*(conf: ConfigRef; modulename, currentModule: string): AbsoluteFile =
   # returns path to module
   var m = addFileExt(modulename, NimExt)
+  var hasRelativeDot = false
   if m.startsWith(pkgPrefix):
     result = findFile(conf, m.substr(pkgPrefix.len), suppressStdlib = true)
   else:
@@ -923,7 +924,11 @@ proc findModule*(conf: ConfigRef; modulename, currentModule: string): AbsoluteFi
     else: # If prefixed with std/ why would we add the current module path!
       let currentPath = currentModule.splitFile.dir
       result = AbsoluteFile currentPath / m
-    if not fileExists(result):
+      if m.startsWith('.') and not fileExists(result):
+        result = AbsoluteFile ""
+        hasRelativeDot = true
+
+    if not fileExists(result) and not hasRelativeDot:
       result = findFile(conf, m)
   patchModule(conf)
 

tests/import/t22065.nim

@@ -0,0 +1,5 @@
+discard """
+  errormsg: "cannot open file: ./sugar"
+"""
+
+import ./sugar