Edit Book: Fix groups in replace template being interpreted backwards when search direction is up

src/regex/__init__.py

@@ -225,7 +225,7 @@ __all__ = ["compile", "escape", "findall", "finditer", "fullmatch", "match",
   "V0", "VERSION0", "V1", "VERSION1", "X", "VERBOSE", "W", "WORD", "error",
   "Regex"]
 
-__version__ = "2.4.64"
+__version__ = "2.4.66"
 
 # --------------------------------------------------------------------
 # Public interface.

src/regex/_regex.c

@@ -11577,6 +11577,8 @@ advance:
             if (try_body) {
                 body_status = try_match(state, &node->next_1, state->text_pos,
                   &next_body_position);
+                if (body_status < 0)
+                    return body_status;
 
                 if (body_status == RE_ERROR_FAILURE)
                     try_body = FALSE;
@@ -11589,6 +11591,8 @@ advance:
             if(try_tail) {
                 tail_status = try_match(state, &node->nonstring.next_2,
                   state->text_pos, &next_tail_position);
+                if (tail_status < 0)
+                    return tail_status;
 
                 if (tail_status == RE_ERROR_FAILURE)
                     try_tail = FALSE;
@@ -11738,6 +11742,8 @@ advance:
             if (try_body) {
                 body_status = try_match(state, &node->next_1, state->text_pos,
                   &next_body_position);
+                if (body_status < 0)
+                    return body_status;
 
                 if (body_status == RE_ERROR_FAILURE)
                     try_body = FALSE;
@@ -11748,6 +11754,8 @@ advance:
             if (try_tail) {
                 tail_status = try_match(state, &node->nonstring.next_2,
                   state->text_pos, &next_tail_position);
+                if (tail_status < 0)
+                    return tail_status;
 
                 if (tail_status == RE_ERROR_FAILURE)
                     try_tail = FALSE;
@@ -12029,6 +12037,8 @@ advance:
             if (try_body) {
                 body_status = try_match(state, &node->next_1, state->text_pos,
                   &next_body_position);
+                if (body_status < 0)
+                    return body_status;
 
                 if (body_status == RE_ERROR_FAILURE)
                     try_body = FALSE;
@@ -12039,6 +12049,8 @@ advance:
             if (try_tail) {
                 tail_status = try_match(state, &node->nonstring.next_2,
                   state->text_pos, &next_tail_position);
+                if (tail_status < 0)
+                    return tail_status;
 
                 if (tail_status == RE_ERROR_FAILURE)
                     try_tail = FALSE;
@@ -12289,6 +12301,8 @@ advance:
             if (try_body) {
                 body_status = try_match(state, &node->next_1, state->text_pos,
                   &next_body_position);
+                if (body_status < 0)
+                    return body_status;
 
                 if (body_status == RE_ERROR_FAILURE)
                     try_body = FALSE;
@@ -12299,6 +12313,8 @@ advance:
             if(try_tail) {
                 tail_status = try_match(state, &node->nonstring.next_2,
                   state->text_pos, &next_tail_position);
+                if (tail_status < 0)
+                    return tail_status;
 
                 if (tail_status == RE_ERROR_FAILURE)
                     try_tail = FALSE;
@@ -14200,11 +14216,17 @@ backtrack:
 
             if (test->status & RE_STATUS_FUZZY) {
                 for (;;) {
+                    int status;
                     RE_Position next_position;
 
                     pos -= step;
 
-                    if (try_match(state, &node->next_1, pos, &next_position) &&
+                    status = try_match(state, &node->next_1, pos,
+                      &next_position);
+                    if (status < 0)
+                        return status;
+
+                    if (status != RE_ERROR_FAILURE &&
                       !is_repeat_guarded(safe_state, index, pos,
                       RE_STATUS_TAIL)) {
                         match = TRUE;
@@ -15742,6 +15764,14 @@ Py_LOCAL_INLINE(int) do_match(RE_SafeState* safe_state, BOOL search) {
         state->lastgroup = -1;
         max_end_index = -1;
 
+        if (status == RE_ERROR_PARTIAL) {
+            /* We've matched up to the limit of the slice. */
+            if (state->reverse)
+                state->text_pos = state->slice_start;
+            else
+                state->text_pos = state->slice_end;
+        }
+
         /* Store the capture groups. */
         group_info = pattern->group_info;
 
@@ -19332,17 +19362,32 @@ Py_LOCAL_INLINE(PyObject*) pattern_subx(PatternObject* self, PyObject*
 #endif
         } else if (is_template) {
             /* The replacement is a list template. */
-            Py_ssize_t size;
+            Py_ssize_t count;
-            Py_ssize_t i;
+            Py_ssize_t index;
+            Py_ssize_t step;
 
             /* Add each part of the template to the list. */
-            size = PyList_GET_SIZE(replacement);
+            count = PyList_GET_SIZE(replacement);
-            for (i = 0; i < size; i++) {
+            if (join_info.reversed) {
+                /* We're searching backwards, so we'll be reversing the list
+                 * when it's complete. Therefore, we need to add the items of
+                 * the template in reverse order for them to be in the correct
+                 * order after the reversal.
+                 */
+                index = count - 1;
+                step = -1;
+            } else {
+                /* We're searching forwards. */
+                index = 0;
+                step = 1;
+            }
+
+            while (count > 0) {
                 PyObject* item;
                 PyObject* str_item;
 
                 /* PyList_GET_ITEM borrows a reference. */
-                item = PyList_GET_ITEM(replacement, i);
+                item = PyList_GET_ITEM(replacement, index);
                 str_item = get_sub_replacement(item, string, &state,
                   self->public_group_count);
                 if (!str_item)
@@ -19358,6 +19403,9 @@ Py_LOCAL_INLINE(PyObject*) pattern_subx(PatternObject* self, PyObject*
                     if (status < 0)
                         goto error;
                 }
+
+                --count;
+                index += step;
             }
         } else if (is_callable) {
             /* Pass a MatchObject to the replacement function. */