SAGA: fix submit 53486 "Added sanity checks for realloc() calls - bug report #3087852". zero count realloc may return NULL as valid value

svn-id: r53614

4 files changed, 23 insertions, 19 deletions

diff --git a/engines/saga/actor.cpp b/engines/saga/actor.cpp
index d44de0d75e..6e6707c2b5 100644
--- a/engines/saga/actor.cpp
+++ b/engines/saga/actor.cpp
@@ -149,10 +149,11 @@ void ActorData::setTileDirectionsSize(int size, bool forceRealloc) {
 	}
 	_tileDirectionsAlloced = size;
 	byte *tmp = (byte*)realloc(_tileDirections, _tileDirectionsAlloced * sizeof(*_tileDirections));
-	if (tmp)
+	if ((tmp != NULL) || (_tileDirectionsAlloced == 0)) {
 		_tileDirections = tmp;
-	else
+	} else {
 		error("ActorData::setTileDirectionsSize(): Error while reallocating memory");
+	}
 }
 
 void ActorData::cycleWrap(int cycleLimit) {
@@ -166,10 +167,11 @@ void ActorData::setWalkStepsPointsSize(int size, bool forceRealloc) {
 	}
 	_walkStepsAlloced = size;
 	Point *tmp = (Point*)realloc(_walkStepsPoints, _walkStepsAlloced * sizeof(*_walkStepsPoints));
-	if (tmp)
+	if ((tmp != NULL) || (_walkStepsAlloced == 0)) {
 		_walkStepsPoints = tmp;
-	else
+	} else {
 		error("ActorData::setWalkStepsPointsSize(): Error while reallocating memory");
+	}
 }
 
 void ActorData::addWalkStepPoint(const Point &point) {
diff --git a/engines/saga/saga.cpp b/engines/saga/saga.cpp
index 13567f67b5..1643ecfa17 100644
--- a/engines/saga/saga.cpp
+++ b/engines/saga/saga.cpp
@@ -426,10 +426,11 @@ void SagaEngine::loadStrings(StringsTable &stringsTable, const byte *stringsPoin
 		if (offset == stringsLength) {
 			stringsCount = i;
 			const char **tmp = (const char **)realloc(stringsTable.strings, stringsCount * sizeof(*stringsTable.strings));
-			if (tmp)
+			if ((tmp != NULL) || (stringsCount == 0)) {
 				stringsTable.strings = tmp;
-			else
+			} else {
 				error("SagaEngine::loadStrings() Error while reallocating memory");
+			}
 			break;
 		}
 		if (offset > stringsLength) {
@@ -438,10 +439,11 @@ void SagaEngine::loadStrings(StringsTable &stringsTable, const byte *stringsPoin
 			warning("SagaEngine::loadStrings wrong strings table");
 			stringsCount = i;
 			const char **tmp = (const char **)realloc(stringsTable.strings, stringsCount * sizeof(*stringsTable.strings));
-			if (tmp)
+			if ((tmp != NULL) || (stringsCount == 0)) {
 				stringsTable.strings = tmp;
-			else
+			} else {
 				error("SagaEngine::loadStrings() Error while reallocating memory");
+			}
 			break;
 		}
 		stringsTable.strings[i] = (const char *)stringsTable.stringsPointer + offset;
diff --git a/engines/saga/shorten.cpp b/engines/saga/shorten.cpp
index 684b3a86bb..8353c7dbad 100644
--- a/engines/saga/shorten.cpp
+++ b/engines/saga/shorten.cpp
@@ -367,10 +367,11 @@ byte *loadShortenFromStream(Common::ReadStream &stream, int &size, int &rate, by
 							warning("Safeguard: maxLPC < lpcNum (should never happen)");
 							maxLPC = lpcNum;
 							int32 *tmp = (int32 *) realloc(lpc, maxLPC * 4);
-							if (tmp)
+							if ((tmp != NULL) || (maxLPC == 0)) {
 								lpc = tmp;
-							else
+							} else {
 								error("loadShortenFromStream(): Error while reallocating memory");
+							}
 						}
 
 						for (i = 0; i < lpcNum; i++)
@@ -435,10 +436,11 @@ byte *loadShortenFromStream(Common::ReadStream &stream, int &size, int &rate, by
 					prevSize = size;
 					size += (blockSize * dataSize);
 					byte *tmp = (byte *) realloc(unpackedBuffer, size);
-					if (tmp)
+					if ((tmp != NULL) || (size == 0)) {
 						unpackedBuffer = tmp;
-					else
+					} else {
 						error("loadShortenFromStream(): Error while reallocating memory");
+					}
 					pBuf = unpackedBuffer + prevSize;
 
 					if (flags & Audio::FLAG_16BITS) {
@@ -473,10 +475,11 @@ byte *loadShortenFromStream(Common::ReadStream &stream, int &size, int &rate, by
 				prevSize = size;
 				size += vLen;
 				byte *tmp = (byte *) realloc(unpackedBuffer, size);
-				if (tmp)
+				if ((tmp != NULL) || (size == 0)) {
 					unpackedBuffer = tmp;
-				else
+				} else {
 					error("loadShortenFromStream(): Error while reallocating memory");
+				}
 				pBuf = unpackedBuffer + prevSize;
 
 				while (vLen--) {
diff --git a/engines/saga/sprite.cpp b/engines/saga/sprite.cpp
index 969faae737..a62f7c57eb 100644
--- a/engines/saga/sprite.cpp
+++ b/engines/saga/sprite.cpp
@@ -116,13 +116,10 @@ void Sprite::loadList(int resourceId, SpriteList &spriteList) {
 	newSpriteCount = spriteList.spriteCount + spriteCount;
 
 	SpriteInfo *tmp = (SpriteInfo *)realloc(spriteList.infoList, newSpriteCount * sizeof(*spriteList.infoList));
-	if (tmp)
+	if ((tmp != NULL) || (newSpriteCount == 0)) {
 		spriteList.infoList = tmp;
-	else
+	} else {
 		error("Sprite::loadList(): Error while reallocating memory");
-
-	if (spriteList.infoList == NULL) {
-		memoryError("Sprite::loadList");
 	}
 
 	spriteList.spriteCount = newSpriteCount;