expr adjust: fix invalid weight with multiple adjusts

[komainu8]

GitHub: fix GH-1548

The weight value that a user specify is pushed in stack.
This value pop in PARSE().
Currently, If we specify multiple weights in search query, Groonga pop the latest weight immediately after Groonga it push in stack.

Therefore, the latest weight doesn't apply result.
As a result, the previous weight is multiple applied.

In this modification, multiple weight are applied correctly by pushing weight in stack after Groonga execute PARSE().

[kou]

Hmm...
We should pop in .lemon because nest information should be processed by Lemon.

It seems that we just need the following change:

diff --git a/lib/expr.c b/lib/expr.c
index 29fa00cea..cd7a13e70 100644
--- a/lib/expr.c
+++ b/lib/expr.c
@@ -4431,8 +4434,8 @@ parse_query_accept_adjust(grn_ctx *ctx,
                           float weight)
 {
   if (!(q->flags & GRN_EXPR_QUERY_NO_SYNTAX_ERROR)) {
-    parse_query_push_weight(ctx, q, weight);
     PARSE(token);
+    parse_query_push_weight(ctx, q, weight);
     return;
   }

[komainu8]

@kou Thank you for your comments.
I've fixed it and I added tests for this modification.

[kou]

Could you revert this?

[kou]

Could you add why/when this problem is happen and how to fix this problem to the pull request description?

[komainu8]

I updated he pull request description.

[kou]

FYI: My version:

GitHub: fix GH-1548

Weights are managed by stack.

Currently, if we specify multiple weights in search query ("<0.1title:@groonga <0.3content:@Full"), Groonga doesn't pops the current weight ("0.1" for "<0.1title:@groonga") after the weight's scope is finished ("0.1" in "<0.1title:@groonga") and the next weight ("0.3" in "<0.3content:@Full") is popped after it's pushed. So the next condition ("content:@Full") uses the first weight ("0.1") not the second weight ("0.3").

Example (| is the current position):

• |<0.1title:@Groonga <0.3content:@full: initial state: (current stack: [0.0])
• <0.1|title:@Groonga <0.3content:@full: push 0.1: (current stack: [0.0, 0.1 (= 0.0 + 0.1 to support nested adjust)])
• <0.1title:@Groonga| <0.3content:@full: title:@Groonga uses 0.1 as weight: (current stack: [0.0, 0.1])
• <0.1title:@Groonga <0.3|content:@full: push 0.3: (current stack: [0.0, 0.1, 0.4 (= 0.1 + 0.3 to support nested adjust)])
• <0.1title:@Groonga <0.3|content:@full: pop: (current stack: [0.0, 0.1])
• <0.1title:@Groonga <0.3content:@full|: content:@full uses 0.1 (not 0.3) as weight: (current stack: [0.0, 0.1]))
• <0.1title:@Groonga <0.3content:@full|: pop: (current stack: [0.0])

Therefore, the latest weight doesn't apply result.
As a result, the previous weight is applied multiple times.

With this change, multiple weights are applied correctly:

• |<0.1title:@Groonga <0.3content:@full: initial state: (current stack: [0.0])
• <0.1|title:@Groonga <0.3content:@full: push 0.1: (current stack: [0.0, 0.1 (= 0.0 + 0.1 to support nested adjust)])
• <0.1title:@Groonga| <0.3content:@full: title:@Groonga uses 0.1 as weight: (current stack: [0.0, 0.1])
• <0.1title:@Groonga <0.3|content:@full: pop: (current stack: [0.0])
• <0.1title:@Groonga <0.3|content:@full: push 0.3: (current stack: [0.0, 0.3 (= 0.0 + 0.3 to support nested adjust)])
• <0.1title:@Groonga <0.3content:@full|: content:@full uses 0.3) as weight: (current stack: [0.0, 0.3]))
• <0.1title:@Groonga <0.3content:@full|: pop: (current stack: [0.0])