From 1830a08c2f97365c0f45c73a0fda4a33a74afb21 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Andr=C3=A9=20Malo?= <nd@apache.org>
Date: Tue, 26 Aug 2003 00:32:03 +0000
Subject: [PATCH] since our parse tree is left-weighted, the short circuit
 evaluation is way more useful if we short circuit the left side. So evaluate
 the right side first. This, however, reverses my statement about regex
 optimization (you have to put them onto the right side of an && or ||
 operator to get a chance that the left side will be cutted).

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@101105 13f79535-47bb-0310-9956-ffa450edef68
---
 modules/filters/mod_include.c | 41 ++++++++++++++++++-----------------
 1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/modules/filters/mod_include.c b/modules/filters/mod_include.c
index 53e0d3f4f4..b210c891b5 100644
--- a/modules/filters/mod_include.c
+++ b/modules/filters/mod_include.c
@@ -1365,50 +1365,51 @@ static int parse_expr(include_ctx_t *ctx, const char *expr, int *was_error)
                 *was_error = 1;
                 return retval;
             }
-            if (!current->left->done) {
-                switch (current->left->token.type) {
+
+            if (!current->right->done) {
+                switch (current->right->token.type) {
                 case TOKEN_STRING:
                     buffer = ap_ssi_parse_string(ctx,
-                                                 current->left->token.value,
+                                                 current->right->token.value,
                                                  NULL, 0, SSI_EXPAND_DROP_NAME);
 
-                    current->left->token.value = buffer;
-                    current->left->value = !!*current->left->token.value;
-                    current->left->done = 1;
+                    current->right->token.value = buffer;
+                    current->right->value = !!*current->right->token.value;
+                    current->right->done = 1;
                     break;
 
                 default:
-                    current = current->left;
+                    current = current->right;
                     continue;
                 }
             }
 
             /* short circuit evaluation */
-            if (!current->right->done && !regex &&
-                ((current->token.type == TOKEN_AND && !current->left->value) ||
-                (current->token.type == TOKEN_OR && current->left->value))) {
-                DEBUG_PRINTF((ctx, "     Left: %c\n", current->left->value
+            if (!current->left->done && !regex &&
+                ((current->token.type == TOKEN_AND && !current->right->value) ||
+                (current->token.type == TOKEN_OR && current->right->value))) {
+                DEBUG_PRINTF((ctx, "     Left: short circuited\n"));
+                DEBUG_PRINTF((ctx, "     Right: %c\n", current->right->value
                                                                   ? '1' : '0'));
-                DEBUG_PRINTF((ctx, "     Right: short circuited\n"));
 
-                current->value = current->left->value;
+                current->value = current->right->value;
             }
             else {
-                if (!current->right->done) {
-                    switch (current->right->token.type) {
+                if (!current->left->done) {
+                    switch (current->left->token.type) {
                     case TOKEN_STRING:
                         buffer = ap_ssi_parse_string(ctx,
-                                                     current->right->token.value,
+                                                     current->left->token.value,
                                                      NULL, 0,
                                                      SSI_EXPAND_DROP_NAME);
 
-                        current->right->token.value = buffer;
-                        current->right->value = !!*current->right->token.value;
-                        current->right->done = 1;
+                        current->left->token.value = buffer;
+                        current->left->value = !!*current->left->token.value;
+                        current->left->done = 1;
                         break;
 
                     default:
-                        current = current->right;
+                        current = current->left;
                         continue;
                     }
                 }
-- 
2.50.1