From 2a313c07eee1864e757d0864d4fe8a430745fd72 Mon Sep 17 00:00:00 2001
From: Cameron Purdy <699204+cpurdy@users.noreply.github.com>
Date: Sat, 11 Jan 2025 16:42:10 -0500
Subject: [PATCH] Patch for URI

---
 lib_net/src/main/x/net/Uri.x         | 11 +++++----
 lib_net/src/main/x/net/UriTemplate.x | 35 +++++++++++++++++++++++-----
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/lib_net/src/main/x/net/Uri.x b/lib_net/src/main/x/net/Uri.x
index c082c7032..640e4ef32 100644
--- a/lib_net/src/main/x/net/Uri.x
+++ b/lib_net/src/main/x/net/Uri.x
@@ -832,6 +832,9 @@ const Uri
                 Int endOffset = totalLength;
                 if (isLast && end.offset < endOffset) {
                     endOffset = end.offset;
+                    if (offset == endOffset) {
+                        return True;
+                    }
                 }
                 if (String prefix ?= section.prefix) {
                     Int partLen = prefix.size;
@@ -839,17 +842,17 @@ const Uri
                         prefix[offset..<endOffset.notGreaterThan(partLen)].appendTo(buf);
                     }
                     offset     = (offset-partLen).notLessThan(0);
-                    endOffset -= partLen;
+                    endOffset  = (endOffset-partLen).notLessThan(0);
                 }
-                if (!text.empty) {
+                if (offset < endOffset && !text.empty) {
                     Int partLen = text.size;
                     if (offset < partLen) {
                         section.escape(buf, text[offset..<endOffset.notGreaterThan(partLen)]);
                     }
                     offset     = (offset-partLen).notLessThan(0);
-                    endOffset -= partLen;
+                    endOffset  = (endOffset-partLen).notLessThan(0);
                 }
-                if (String suffix ?= section.suffix) {
+                if (offset < endOffset, String suffix ?= section.suffix) {
                     Int partLen = suffix.size;
                     if (offset < partLen) {
                         suffix[offset..<endOffset.notGreaterThan(partLen)].appendTo(buf);
diff --git a/lib_net/src/main/x/net/UriTemplate.x b/lib_net/src/main/x/net/UriTemplate.x
index 2ff567dd6..808015984 100644
--- a/lib_net/src/main/x/net/UriTemplate.x
+++ b/lib_net/src/main/x/net/UriTemplate.x
@@ -442,6 +442,13 @@ const UriTemplate {
         @Override
         @RO Char prefix;
 
+        @RO Value defaultValue.get() = "";
+
+        @RO Value defaultExplodedValue.get() {
+            static String[] EmptyArray = [];
+            return EmptyArray;
+        }
+
         @Override
         Appender<Char> expand(Appender<Char> buf, Lookup values) {
             for (Variable var : vars) {
@@ -482,24 +489,34 @@ const UriTemplate {
         @Override
         conditional (Position after, Map<String, Value> bindings) matches(Uri uri,
                 Position from, Position? to, Char? nextPrefix, Map<String, Value> bindings) {
+            // we can only match if we are inside the correct section
+            if (!(from := uri.positionAt(from, onlyWithin))) {
+                return False;
+            }
+
             String sectionText   = uri.sectionText(onlyWithin);
             Int    sectionLength = sectionText.size;
             if (sectionLength == 0) {
+                if (prefix == nextPrefix) {
+                    // this is a conservative decision, but will not always be correct; the
+                    // assumption here is that a multi-part section can't have multiple parts
+                    // if it doesn't have any parts; it may need to be re-worked if a use case
+                    // arises where multiple empty parts are desired
+                    return False;
+                }
                 for (Variable var : vars) {
                     if (var.require) {
                         // no text, no match (because even the prefix is absent)
                         return False;
+                    } else {
+                        bindings = mutate(bindings).put(var.name, var.explode ? defaultExplodedValue : defaultValue);
                     }
                 }
+                return True, from, bindings;
             }
 
-            // we can only match if we are inside the correct section
-            if (!(from := uri.positionAt(from, onlyWithin))) {
-                return False;
-            }
             Int fromOffset = from.offset;
-
-            Int toOffset = sectionLength;
+            Int toOffset   = sectionLength;
             to := uri.positionAt(to?, onlyWithin);
             switch (to?.section <=> onlyWithin) {
             case Lesser:
@@ -613,6 +630,12 @@ const UriTemplate {
             return '?';
         }
 
+        @Override
+        Value defaultExplodedValue.get() {
+            static Map<String,String> EmptyMap = [];
+            return EmptyMap;
+        }
+
         @Override
         conditional (Position after, Map<String, Value> bindings) matches(Uri uri,
                 Position from, Position? to, Char? nextPrefix, Map<String, Value> bindings) {