Fix losing data due to a mistake in the lazy implementation

1 files changed, 45 insertions, 49 deletions

diff --git a/src/cc4group.c b/src/cc4group.c
index 6766745..df8854a 100644
--- a/src/cc4group.c
+++ b/src/cc4group.c
@@ -640,10 +640,9 @@ static bool cc4group_uncompressUntilPosition(CC4Group* const this, size_t const
 	}
 
 	assert(rootGroup);
-	assert(rootGroup->readState.active);
 	assert(position <= rootGroup->uncompressedSize);
 
-	if(rootGroup->readState.position < position)
+	if(rootGroup->readState.active && rootGroup->readState.position < position)
 	{
 		rootGroup->readState.gzStrm.avail_out = position - rootGroup->readState.position;
 
@@ -2041,63 +2040,60 @@ static void cc4group_mmappedFileManagementEnd(void* const data, void* const arg)
 
 static const uint8_t* cc4group_getOnlyEntryData(CC4Group* const this, const C4GroupEntryData* entry)
 {
-	if(entry->data == NULL)
+	if(this->lazy)
 	{
-		if(entry->path != NULL)
+		if(!cc4group_uncompressUntilPosition(this, entry->absolutePosition + entry->core.Size))
 		{
-			int file = open(entry->path, O_RDONLY | O_BINARY);
-			if(file == -1)
-			{
-				SET_ERRNO_ERROR("open: Opening the needed file");
-				return NULL;
-			}
-
-			void* mapped = cc4group_mmap(NULL, entry->core.Size, PROT_READ, MAP_PRIVATE, file, 0);
-			if(mapped == MAP_FAILED)
-			{
-				SET_ERRNO_ERROR("mmap: Mapping the file to add/load from disk");
-				if(close(file) == -1)
-				{
-					cc4group_warn(this, "close: after mmapping the file \"%s\" failed, closing it failed too: %s", entry->path, strerror(errno));
-				}
-				return NULL;
-			}
-
-			CC4GroupMMappedFileManagement* management = malloc(sizeof(*management));
-			if(management == NULL)
-			{
-				SET_ERRNO_ERROR("malloc: allocating memory for temporary memory management");
-				return NULL;
-			}
+			return NULL;
+		}
 
-			*management = (CC4GroupMMappedFileManagement){
-				.management = {
-					.start = cc4group_mmappedFileManagementStart,
-					.end = cc4group_mmappedFileManagementEnd,
-					.arg = management
-				},
-				.size = entry->core.Size,
-				.fd = -1,
-				.group = this
-			};
+		((C4GroupEntryData*)entry)->data = this->uncompressedData + entry->absolutePosition;
+	}
+	else if(entry->path != NULL && entry->data == NULL)
+	{
+		int file = open(entry->path, O_RDONLY | O_BINARY);
+		if(file == -1)
+		{
+			SET_ERRNO_ERROR("open: Opening the needed file");
+			return NULL;
+		}
 
+		void* mapped = cc4group_mmap(NULL, entry->core.Size, PROT_READ, MAP_PRIVATE, file, 0);
+		if(mapped == MAP_FAILED)
+		{
+			SET_ERRNO_ERROR("mmap: Mapping the file to add/load from disk");
 			if(close(file) == -1)
 			{
-				management->fd = file;
+				cc4group_warn(this, "close: after mmapping the file \"%s\" failed, closing it failed too: %s", entry->path, strerror(errno));
 			}
-
-			((C4GroupEntryData*)entry)->data = mapped;
-			((C4GroupEntryData*)entry)->memoryManagement = &management->management;
+			return NULL;
 		}
-		else
+
+		CC4GroupMMappedFileManagement* management = malloc(sizeof(*management));
+		if(management == NULL)
 		{
-			if(!cc4group_uncompressUntilPosition(this, entry->absolutePosition + entry->core.Size))
-			{
-				return NULL;
-			}
+			SET_ERRNO_ERROR("malloc: allocating memory for temporary memory management");
+			return NULL;
+		}
 
-			((C4GroupEntryData*)entry)->data = this->uncompressedData + entry->absolutePosition;
+		*management = (CC4GroupMMappedFileManagement){
+			.management = {
+				.start = cc4group_mmappedFileManagementStart,
+				.end = cc4group_mmappedFileManagementEnd,
+				.arg = management
+			},
+			.size = entry->core.Size,
+			.fd = -1,
+			.group = this
+		};
+
+		if(close(file) == -1)
+		{
+			management->fd = file;
 		}
+
+		((C4GroupEntryData*)entry)->data = mapped;
+		((C4GroupEntryData*)entry)->memoryManagement = &management->management;
 	}
 
 	return entry->data;
@@ -2380,7 +2376,7 @@ static bool cc4group_deflateToCallback(WriteCallback* const callback, const void
 
 static bool cc4group_writeEntries(CC4Group* const this, C4GroupEntryData* const entryData, WriteCallback* const callback)
 {
-	const C4GroupHeader* origHeader = (const C4GroupHeader*)cc4group_getOnlyEntryData(this, entryData);
+	const C4GroupHeader* origHeader = cc4group_getHeader(this, entryData);
 	if(origHeader == NULL)
 	{
 		return false;