Rust: Start canonical path part indices at zero

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 4e7f3f7f-82b3-403c-93fa-984f56c89a70

Author: hvitved

rust/ql/lib/codeql/rust/internal/PathResolution.qll

@@ -1104,32 +1104,32 @@ final class TraitItemNode extends ImplOrTraitItemNode, NamedItemNode, TypeItemNo
 
   bindingset[c]
   private string getCanonicalPathPart(Crate c, int i) {
-    i = -1 and
+    i = 0 and
     result = "<"
     or
-    i = 0 and
+    i = 1 and
     result = this.getCanonicalPathPrefix(c)
     or
-    i = 1 and
+    i = 2 and
     result = "::"
     or
-    i = 2 and
+    i = 3 and
     result = this.getName()
     or
-    i = 3 and
+    i = 4 and
     result = ">"
   }
 
   language[monotonicAggregates]
   override string getCanonicalPath(Crate c) {
     this.hasCanonicalPath(c) and
-    result = strictconcat(int i | i in [0 .. 2] | this.getCanonicalPathPart(c, i) order by i)
+    result = strictconcat(int i | i in [1 .. 3] | this.getCanonicalPathPart(c, i) order by i)
   }
 
   language[monotonicAggregates]
   override string getCanonicalPathPrefixFor(Crate c, ItemNode child) {
     this.providesCanonicalPathPrefixFor(c, child) and
-    result = strictconcat(int i | i in [-1 .. 3] | this.getCanonicalPathPart(c, i) order by i)
+    result = strictconcat(int i | i in [0 .. 4] | this.getCanonicalPathPart(c, i) order by i)
   }
 }