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

diff --git a/modules/filters/mod_include.c b/modules/filters/mod_include.c
index 53e0d3f4f4a1255339286563318f9216eda35a30..b210c891b535fde7692cc9f4d3ff8e36e11544ee 100644 (file)
--- 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;
                     }
                 }