From 2a7bf2ede27edcf32bdff3801ab81daac224da38 Mon Sep 17 00:00:00 2001
From: Alde Rojas <hello@alde.dev>
Date: Wed, 24 Dec 2025 01:39:41 -0600
Subject: [PATCH] common : use regex_search with anchoring for partial matching

---
 common/regex-partial.cpp | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/common/regex-partial.cpp b/common/regex-partial.cpp
index 4bff6b6633..e667a209e9 100644
--- a/common/regex-partial.cpp
+++ b/common/regex-partial.cpp
@@ -27,7 +27,7 @@ common_regex_match common_regex::search(const std::string & input, size_t pos, b
         return res;
     }
     std::match_results<std::string::const_reverse_iterator> srmatch;
-    if (std::regex_match(input.rbegin(), input.rend() - pos, srmatch, rx_reversed_partial)) {
+    if (std::regex_search(input.rbegin(), input.rend() - pos, srmatch, rx_reversed_partial, std::regex_constants::match_continuous)) {
         auto group = srmatch[1].str();
         if (group.length() != 0) {
             auto it = srmatch[1].second.base();
@@ -55,18 +55,18 @@ common_regex_match common_regex::search(const std::string & input, size_t pos, b
   to see if a string ends with a partial regex match, but but it's not in std::regex yet.
   Instead, we'll the regex into a partial match regex operating as a full match on the reverse iterators of the input.
 
-  - /abcd/ -> (dcba|cba|ba|a).* -> ((?:(?:(?:(?:d)?c)?b)?a).*
-  - /a|b/ -> (a|b).*
+  - /abcd/ -> ^(dcba|cba|ba|a) -> ^((?:(?:(?:(?:d)?c)?b)?a)
+  - /a|b/ -> ^(a|b)
   - /a*?/ -> error, could match ""
-  - /a*b/ -> ((?:b)?a*+).* (final repetitions become eager)
-  - /.*?ab/ -> ((?:b)?a).* (merge .*)
-  - /a.*?b/ -> ((?:b)?.*?a).* (keep reluctant matches)
-  - /a(bc)d/ -> ((?:(?:d)?(?:(?:c)?b))?a).*
-  - /a(bc|de)/ -> ((?:(?:(?:e)?d)?|(?:(?:c)?b)?)?a).*
-  - /ab{2,4}c/ -> abbb?b?c -> ((?:(?:(?:(?:(?:c)?b)?b)?b?)?b?)?a).*
+  - /a*b/ -> ^((?:b)?a*+) (final repetitions become eager)
+  - /.*?ab/ -> ^((?:b)?a) (omit .*)
+  - /a.*?b/ -> ^((?:b)?.*?a) (keep reluctant matches)
+  - /a(bc)d/ -> ^((?:(?:d)?(?:(?:c)?b))?a)
+  - /a(bc|de)/ -> ^((?:(?:(?:e)?d)?|(?:(?:c)?b)?)?a)
+  - /ab{2,4}c/ -> ^cbbb?b?a -> ^((?:(?:(?:(?:(?:c)?b)?b)?b?)?b?)?a)
 
-  The regex will match a reversed string fully, and the end of the first (And only) capturing group will indicate the reversed start of the original partial pattern
-  (i.e. just where the final .* starts in the inverted pattern; all other groups are turned into non-capturing groups, and reluctant quantifiers are ignored)
+  The regex will match a reversed string fully, and the end of the first (And only) capturing group will indicate the reversed start of the original partial pattern.
+  All other groups are turned into non-capturing groups, and reluctant quantifiers are ignored.
 */
 std::string regex_to_reversed_partial_regex(const std::string & pattern) {
     auto it = pattern.begin();
@@ -177,7 +177,7 @@ std::string regex_to_reversed_partial_regex(const std::string & pattern) {
             }
         }
 
-        // /abcd/ -> (dcba|cba|ba|a).* -> ((?:(?:(?:d)?c)?b)?a).*
+        // /abcd/ -> ^(dcba|cba|ba|a) -> ^((?:(?:(?:d)?c)?b)?a)
         // if n(=4) parts, opening n-1(=3) non-capturing groups after the 1 capturing group
         // We'll do the outermost capturing group and final .* in the enclosing function.
         std::vector<std::string> res_alts;
@@ -200,5 +200,5 @@ std::string regex_to_reversed_partial_regex(const std::string & pattern) {
         throw std::runtime_error("Unmatched '(' in pattern");
     }
 
-    return "(" + res + ")[\\s\\S]*";
+    return "^(" + res + ")";
 }