system. for cstrings uses value comparisons, not reference comparisons

lib/system.nim

@@ -302,8 +302,7 @@ proc `==` *(x, y: pointer): bool {.magic: "EqRef", noSideEffect.}
   ##  echo (a == b) # true due to the special meaning of `nil`/0 as a pointer
 proc `==` *(x, y: string): bool {.magic: "EqStr", noSideEffect.}
   ## Checks for equality between two `string` variables
-proc `==` *(x, y: cstring): bool {.magic: "EqCString", noSideEffect.}
-  ## Checks for equality between two `cstring` variables
+
 proc `==` *(x, y: char): bool {.magic: "EqCh", noSideEffect.}
   ## Checks for equality between two `char` variables
 proc `==` *(x, y: bool): bool {.magic: "EqB", noSideEffect.}
@@ -3616,6 +3615,16 @@ proc xlen*[T](x: seq[T]): int {.magic: "XLenSeq", noSideEffect.} =
   ## This is an optimization that rarely makes sense.
   discard
 
+
+proc `==` *(x, y: cstring): bool {.magic: "EqCString", noSideEffect,
+                                   inline.} =
+  ## Checks for equality between two `cstring` variables.
+  proc strcmp(a, b: cstring): cint {.noSideEffect,
+    importc, header: "<string.h>".}
+  if pointer(x) == pointer(y): result = true
+  elif x.isNil or y.isNil: result = false
+  else: result = strcmp(x, y) == 0
+
 {.pop.} #{.push warning[GcMem]: off, warning[Uninit]: off.}
 
 when defined(nimconfig):