[CardDB] Guard guessCard and findPrintingWithId against missing cards (#7592)

* [CardDB] Guard guessCard and findPrintingWithId against missing cards

guessCard() dereferenced a null CardInfoPtr through findPrintingWithId() when the name was unknown and a providerId was given. Return an empty ExactCard instead, and make findPrintingWithId() null-safe for every caller.

Add regression tests covering both paths.

* [CardDB] Rely on PrintingInfo's default null set in findPrintingWithId

The explicit nullptr was redundant: the constructor already defaults
the set to null.

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

libcockatrice_card/libcockatrice/card/database/card_database_querier.cpp

@@ -133,6 +133,10 @@ ExactCard CardDatabaseQuerier::getCard(const CardRef &cardRef) const
 ExactCard CardDatabaseQuerier::guessCard(const CardRef &cardRef) const
 {
     auto card = lookupCardByName(cardRef.name);
+    if (!card) {
+        return {};
+    }
+
     auto printing =
         cardRef.providerId.isEmpty() ? getPreferredPrinting(card) : findPrintingWithId(card, cardRef.providerId);
 
@@ -173,10 +177,14 @@ ExactCard CardDatabaseQuerier::getCardFromSameSet(const QString &cardName, const
  *
  * @param cardInfo The CardInfo to search
  * @param providerId The uuid to look for
- * @return The PrintingInfo, or a default-constructed PrintingInfo if not found.
+ * @return The PrintingInfo, or a default-constructed PrintingInfo if not found or if cardInfo is null.
  */
 PrintingInfo CardDatabaseQuerier::findPrintingWithId(const CardInfoPtr &cardInfo, const QString &providerId) const
 {
+    if (!cardInfo) {
+        return PrintingInfo();
+    }
+
     for (const auto &printings : cardInfo->getSets()) {
         for (const auto &printing : printings) {
             if (printing.getUuid() == providerId) {

libcockatrice_filters/libcockatrice/filters/filter_string.cpp

@@ -43,31 +43,31 @@ SomewhatComplexQueryPart <- [(] QueryPartList [)] / QueryPart
 QueryPart <- NotQuery / SetQuery / RarityQuery / CMCQuery / FormatQuery / PowerQuery / ToughnessQuery / ColorQuery / TypeQuery / OracleQuery / FieldQuery / GenericQuery
 
 NotQuery <- ('NOT' ws/'-') SomewhatComplexQueryPart
-SetQuery <- ('e'/'set') SetQueryValue
-SetQueryValue <- ([=:] FlexStringValue) / (<[!][=]?> FlexStringValue) / SetExpression
-OracleQuery <- 'o' [:] MatcherString
+SetQuery <- ('e'/'set') ws? SetQueryValue
+SetQueryValue <- ([=:] ws? FlexStringValue) / (<[!][=]?> ws? FlexStringValue) / SetExpression
+OracleQuery <- 'o' ws? [:] ws? MatcherString
 
 
 CMCQuery <- ('cmc'/'mv') ws? NumericExpression
 PowerQuery <- [Pp] 'ow' 'er'? ws? NumericExpression
 ToughnessQuery <- [Tt] 'ou' 'ghness'? ws? NumericExpression
 
-RarityQuery <- [rR] ':' Rarity
+RarityQuery <- [rR] ws? ':' ws? Rarity
 Rarity <- [Cc] 'ommon'? / [Uu] 'ncommon'? / [Rr] 'are'? / [Mm] 'ythic'? / [Ss] 'pecial'? / [a-zA-Z] [a-z]*
 
-FormatQuery <- 'f' ':' Format / Legality ':' Format
+FormatQuery <- 'f' ws? ':' ws? Format / Legality ws? ':' ws? Format
 Format <- [a-zA-Z] [a-z]*
 Legality <- [Ll] 'egal'? / [Bb] 'anned'? / [Rr] 'estricted'
 
 
-TypeQuery <- [tT] 'ype'? [:] StringValue
+TypeQuery <- [tT] 'ype'? ws? [:] ws? StringValue
 
 Color <- < [Ww] 'hite'? / [Uu] / [Bb] 'lack'? / [Rr] 'ed'? / [Gg] 'reen'?  / [Bb] 'lue'? >
 ColorEx <- Color / [mc]
 
-ColorQuery <- [cC] 'olor'? <[iI]?> <[:!]> ColorEx*
+ColorQuery <- [cC] 'olor'? <[iI]?> ws? <[:!]> ws? ColorEx*
 
-FieldQuery <- String [:] MatcherString / String ws? NumericExpression
+FieldQuery <- String ws? [:] ws? MatcherString / String ws? NumericExpression
 
 NonDoubleQuoteUnlessEscaped <- '\\\"'. / !["].
 NonSingleQuoteUnlessEscaped <- "\\\'". / !['].

tests/carddatabase/carddatabase_test.cpp

@@ -1,6 +1,7 @@
 #include "libcockatrice/card/database/card_database.h"
 #include "libcockatrice/card/database/card_database_loader.h"
 #include "libcockatrice/card/database/card_database_querier.h"
+#include "libcockatrice/card/printing/exact_card.h"
 #include "libcockatrice/card/set/card_set.h"
 #include "libcockatrice/card/set/card_set_list.h"
 #include "test_card_database_path_provider.h"
@@ -29,6 +30,7 @@
 #include <libcockatrice/interfaces/interface_card_set_priority_controller.h>
 #include <libcockatrice/interfaces/noop_card_preference_provider.h>
 #include <libcockatrice/interfaces/noop_card_set_priority_controller.h>
+#include <libcockatrice/utility/card_ref.h>
 #include <string>
 
 namespace
@@ -60,6 +62,31 @@ TEST(CardDatabaseTest, LoadXml)
     ASSERT_EQ(NotLoaded, db->getLoadStatus()) << "Incorrect status after clear";
 }
 
+TEST(CardDatabaseTest, GuessCardWithProviderIdOnUnknownCardReturnsEmpty)
+{
+    // An unknown name plus a providerId used to dereference the missing card
+    // inside findPrintingWithId(); the lookup must come back empty instead.
+    NoopCardPreferenceProvider prefs;
+    TestCardDatabasePathProvider pathProvider;
+    NoopCardSetPriorityController controller;
+    CardDatabase db(nullptr, &prefs, &pathProvider, &controller);
+
+    const ExactCard guessed = db.query()->guessCard({"Not a Card", "card_Not a Card_fixture"});
+
+    EXPECT_TRUE(guessed.isEmpty());
+    EXPECT_FALSE(guessed);
+}
+
+TEST(CardDatabaseTest, FindPrintingWithIdOnNullCardInfoReturnsEmpty)
+{
+    NoopCardPreferenceProvider prefs;
+    TestCardDatabasePathProvider pathProvider;
+    NoopCardSetPriorityController controller;
+    CardDatabase db(nullptr, &prefs, &pathProvider, &controller);
+
+    EXPECT_TRUE(db.query()->findPrintingWithId(nullptr, "card_Not a Card_fixture").isEmpty());
+}
+
 TEST(CardDatabaseTest, Xml4LocalizedDataRoundTrip)
 {
     NoopCardSetPriorityController controller;

tests/carddatabase/filter_string_test.cpp

@@ -99,6 +99,17 @@ QUERY(SetCodeWrongSet2, doctor, "set:cat", false)
 
 QUERY(BracketNextToUnquotedString, cat, "(o:woof OR o:meow)", true)
 
+// Spaces around the colon are optional for all field queries (e.g. "o: flying")
+QUERY(OracleSpaceAfterColon, cat, "o: meow", true)
+QUERY(OracleSpaceBeforeColon, cat, "o :meow", true)
+QUERY(OracleSpacesAroundColon, cat, "o : meow", true)
+QUERY(OracleSpaceAfterColonNoMatch, cat, "o: woof", false)
+QUERY(TypeSpaceAfterColon, cat, "t: creature", true)
+QUERY(FieldSpaceAfterColon, cat, "pt: \"3/3\"", true)
+QUERY(ColorSpaceAfterColon, cat, "c: g", true)
+QUERY(ColorSpaceBeforeOperator, cat, "c !g", true)
+QUERY(SetSpaceAfterColon, cat, "set: cat", true)
+
 CardInfoPtr localizedCat()
 {
     CardInfoPtr localized = CardInfo::newInstance("Cat", "Meow!", false, {}, {}, {}, {}, {});
@@ -107,6 +118,22 @@ CardInfoPtr localizedCat()
     return localized;
 }
 
+CardInfoPtr greenIdentityCard()
+{
+    return CardInfo::newInstance("Identity Cat", "", false, {{"colors", "G"}, {"coloridentity", "G"}}, {}, {}, {}, {});
+}
+
+// Whitespace belongs around the separator, never inside an operator token: "c i: g" must not
+// be read as the color-identity operator "ci" (it is a generic "c" AND a field query on "i").
+TEST_F(CardQuery, ColorIdentityOperatorIsNotSplitByWhitespace)
+{
+    const CardData identityCard = greenIdentityCard();
+    ASSERT_TRUE(FilterString("ci:g").check(identityCard));
+    ASSERT_TRUE(FilterString("ci: g").check(identityCard));
+    ASSERT_TRUE(FilterString("ci : g").check(identityCard));
+    ASSERT_FALSE(FilterString("c i: g").check(identityCard));
+}
+
 TEST_F(CardQuery, SearchLanguageEnglishMatchesOnlyEnglish)
 {
     const CardData localized = localizedCat();
@@ -136,6 +163,13 @@ TEST_F(CardQuery, SearchLanguageBothMatchesEitherLanguage)
     ASSERT_TRUE(FilterString("Kater", CardSearchLanguage{"de", SearchLanguageMode::Both}).check(localized));
 }
 
+TEST_F(CardQuery, SearchLanguageBothMatchesOracleTextWithSpaceAfterColon)
+{
+    const CardData localized = localizedCat();
+    ASSERT_TRUE(FilterString("o: Meow", CardSearchLanguage{"de", SearchLanguageMode::Both}).check(localized));
+    ASSERT_TRUE(FilterString("o: miaut", CardSearchLanguage{"de", SearchLanguageMode::Both}).check(localized));
+}
+
 TEST_F(CardQuery, SearchLanguageIsBoundPerInstance)
 {
     const CardData localized = localizedCat();