From 09bc3aed4f8267126d144e379c4fc14e4954113d Mon Sep 17 00:00:00 2001
From: Duncan Ogilvie <mr.exodia.tpodt@gmail.com>
Date: Mon, 10 Oct 2022 14:34:17 +0200
Subject: [PATCH] Remove footguns from a few APIs

---
 src/dbg/_dbgfunctions.cpp |  7 +++++++
 src/dbg/_exports.cpp      | 15 +++++++--------
 src/dbg/stackinfo.cpp     |  8 ++++++++
 src/dbg/thread.cpp        |  6 ++++--
 4 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/src/dbg/_dbgfunctions.cpp b/src/dbg/_dbgfunctions.cpp
index 71603122..8f2fd420 100644
--- a/src/dbg/_dbgfunctions.cpp
+++ b/src/dbg/_dbgfunctions.cpp
@@ -127,6 +127,10 @@ static void _getsehchain(DBGSEHCHAIN* sehchain)
             MemRead(SEHList[i] + 4, &sehchain->records[i].handler, sizeof(duint));
         }
     }
+    else
+    {
+        sehchain->records = nullptr;
+    }
 }
 
 static bool _getjitauto(bool* jit_auto)
@@ -183,7 +187,10 @@ static bool _getprocesslist(DBGPROCESSINFO** entries, int* count)
         return false;
     *count = (int)infoList.size();
     if(!*count)
+    {
+        *entries = nullptr;
         return false;
+    }
     *entries = (DBGPROCESSINFO*)BridgeAlloc(*count * sizeof(DBGPROCESSINFO));
     for(int i = 0; i < *count; i++)
     {
diff --git a/src/dbg/_exports.cpp b/src/dbg/_exports.cpp
index e3cbf6e5..9c34f25d 100644
--- a/src/dbg/_exports.cpp
+++ b/src/dbg/_exports.cpp
@@ -61,8 +61,8 @@ extern "C" DLL_EXPORT bool _dbg_memmap(MEMMAP* memmap)
     SHARED_ACQUIRE(LockMemoryPages);
 
     int pagecount = (int)memoryPages.size();
-    memset(memmap, 0, sizeof(MEMMAP));
     memmap->count = pagecount;
+    memmap->page = nullptr;
     if(!pagecount)
         return true;
 
@@ -802,13 +802,14 @@ extern "C" DLL_EXPORT int _dbg_getbplist(BPXTYPE type, BPMAP* bpmap)
 {
     if(!bpmap)
         return 0;
+
+    bpmap->count = 0;
+    bpmap->bp = nullptr;
+
     std::vector<BREAKPOINT> list;
     int bpcount = BpGetList(&list);
     if(bpcount == 0)
-    {
-        bpmap->count = 0;
         return 0;
-    }
 
     int retcount = 0;
     std::vector<BRIDGEBP> bridgeList;
@@ -847,10 +848,7 @@ extern "C" DLL_EXPORT int _dbg_getbplist(BPXTYPE type, BPMAP* bpmap)
         retcount++;
     }
     if(!retcount)
-    {
-        bpmap->count = retcount;
-        return retcount;
-    }
+        return 0;
     bpmap->count = retcount;
     bpmap->bp = (BRIDGEBP*)BridgeAlloc(sizeof(BRIDGEBP) * retcount);
     for(int i = 0; i < retcount; i++)
@@ -1395,6 +1393,7 @@ extern "C" DLL_EXPORT duint _dbg_sendmessage(DBGMSG type, void* param1, void* pa
 
         if(info->refcount == 0)
         {
+            info->references = nullptr;
             return false;
         }
         else
diff --git a/src/dbg/stackinfo.cpp b/src/dbg/stackinfo.cpp
index 7434dc4c..90872962 100644
--- a/src/dbg/stackinfo.cpp
+++ b/src/dbg/stackinfo.cpp
@@ -452,6 +452,10 @@ void stackgetcallstackbythread(HANDLE thread, CALLSTACK* callstack)
         // Copy data directly from the vector
         memcpy(callstack->entries, callstackVector.data(), callstack->total * sizeof(CALLSTACKENTRY));
     }
+    else
+    {
+        callstack->entries = nullptr;
+    }
 }
 
 void stackgetcallstack(duint csp, CALLSTACK* callstack)
@@ -469,6 +473,10 @@ void stackgetcallstack(duint csp, CALLSTACK* callstack)
         // Copy data directly from the vector
         memcpy(callstack->entries, callstackVector.data(), callstack->total * sizeof(CALLSTACKENTRY));
     }
+    else
+    {
+        callstack->entries = nullptr;
+    }
 }
 
 void stackupdatesettings()
diff --git a/src/dbg/thread.cpp b/src/dbg/thread.cpp
index 9109e3ea..00b753e2 100644
--- a/src/dbg/thread.cpp
+++ b/src/dbg/thread.cpp
@@ -101,10 +101,12 @@ void ThreadGetList(THREADLIST* List)
     // Also assume BridgeAlloc zeros the returned buffer.
     //
     List->count = (int)threadList.size();
-    List->list = nullptr;
 
-    if(List->count <= 0)
+    if(List->count == 0)
+    {
+        List->list = nullptr;
         return;
+    }
 
     // Allocate C-style array
     List->list = (THREADALLINFO*)BridgeAlloc(List->count * sizeof(THREADALLINFO));