From 1e40b689b239b560c22a06a24145844d936c57d3 Mon Sep 17 00:00:00 2001
From: hendricks266 <hendricks266@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Thu, 24 Sep 2015 06:31:55 +0000
Subject: [PATCH] C-CON: Correct handling of size-zero gamearrays: Prevent a
 crash upon loading a savegame containing them, and allow resizearray to zero.

git-svn-id: https://svn.eduke32.com/eduke32@5355 1a8010ca-5511-0410-912e-c29ae57300e0
---
 polymer/eduke32/source/gameexec.c | 22 ++++++++++++++--------
 polymer/eduke32/source/gamevars.c | 19 +++++++++++++++----
 polymer/eduke32/source/savegame.c |  5 +++--
 3 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/polymer/eduke32/source/gameexec.c b/polymer/eduke32/source/gameexec.c
index 80866a591..2159c347d 100644
--- a/polymer/eduke32/source/gameexec.c
+++ b/polymer/eduke32/source/gameexec.c
@@ -4579,9 +4579,13 @@ finish_qsprintf:
 
                     int32_t numelts = kfilelength(fil) / sizeof(int32_t);
 
-                    // NOTE: LunaCON is stricter: if the file has no
-                    // elements, resize the array to size zero.
-                    if (numelts > 0)
+                    if (numelts == 0)
+                    {
+                        Baligned_free(aGameArrays[j].plValues);
+                        aGameArrays[j].plValues = NULL;
+                        aGameArrays[j].size = numelts;
+                    }
+                    else if (numelts > 0)
                     {
                         int32_t numbytes = numelts * sizeof(int32_t);
 #ifdef BITNESS64
@@ -4644,18 +4648,20 @@ finish_qsprintf:
                 const int32_t newSize = Gv_GetVarX(*insptr++);
                 const int32_t oldSize = aGameArrays[tw].size;
 
-                if (newSize > 0 && newSize != oldSize)
+                if (newSize >= 0 && newSize != oldSize)
                 {
 //                    OSD_Printf(OSDTEXT_GREEN "CON_RESIZEARRAY: resizing array %s from %d to %d\n",
 //                               aGameArrays[j].szLabel, aGameArrays[j].size, newSize);
-                    intptr_t *const tmpar = (intptr_t *)Xmalloc(GAR_ELTSZ * oldSize);
-                    memcpy(tmpar, aGameArrays[tw].plValues, GAR_ELTSZ * oldSize);
+                    intptr_t *const tmpar = oldSize != 0 ? (intptr_t *)Xmalloc(GAR_ELTSZ * oldSize) : NULL;
+                    if (oldSize != 0)
+                        memcpy(tmpar, aGameArrays[tw].plValues, GAR_ELTSZ * oldSize);
 
                     Baligned_free(aGameArrays[tw].plValues);
-                    aGameArrays[tw].plValues = (intptr_t *)Xaligned_alloc(ACTOR_VAR_ALIGNMENT, GAR_ELTSZ * newSize);
+                    aGameArrays[tw].plValues = newSize != 0 ? (intptr_t *)Xaligned_alloc(ACTOR_VAR_ALIGNMENT, GAR_ELTSZ * newSize) : NULL;
                     aGameArrays[tw].size = newSize;
 
-                    memcpy(aGameArrays[tw].plValues, tmpar, GAR_ELTSZ * min(oldSize, newSize));
+                    if (oldSize != 0)
+                        memcpy(aGameArrays[tw].plValues, tmpar, GAR_ELTSZ * min(oldSize, newSize));
                     if (newSize > oldSize)
                         memset(&aGameArrays[tw].plValues[oldSize], 0, GAR_ELTSZ * (newSize - oldSize));
                 }
diff --git a/polymer/eduke32/source/gamevars.c b/polymer/eduke32/source/gamevars.c
index ce50ed2f1..d0e6b3bbb 100644
--- a/polymer/eduke32/source/gamevars.c
+++ b/polymer/eduke32/source/gamevars.c
@@ -189,8 +189,14 @@ int32_t Gv_ReadSave(int32_t fil, int32_t newbehav)
             goto corrupt;
         hash_add(&h_arrays, aGameArrays[i].szLabel, i, 1);
 
-        aGameArrays[i].plValues = (intptr_t *)Xaligned_alloc(ACTOR_VAR_ALIGNMENT, aGameArrays[i].size * GAR_ELTSZ);
-        if (kdfread(aGameArrays[i].plValues, GAR_ELTSZ * aGameArrays[i].size, 1, fil) < 1) goto corrupt;
+        intptr_t const asize = aGameArrays[i].size;
+        if (asize != 0)
+        {
+            aGameArrays[i].plValues = (intptr_t *)Xaligned_alloc(ACTOR_VAR_ALIGNMENT, asize * GAR_ELTSZ);
+            if (kdfread(aGameArrays[i].plValues, GAR_ELTSZ * aGameArrays[i].size, 1, fil) < 1) goto corrupt;
+        }
+        else
+            aGameArrays[i].plValues = NULL;
     }
 
     //  Bsprintf(g_szBuf,"CP:%s %d",__FILE__,__LINE__);
@@ -466,8 +472,13 @@ int32_t Gv_NewArray(const char *pszLabel, void *arrayptr, intptr_t asize, uint32
     if (!(dwFlags & GAMEARRAY_TYPE_MASK))
     {
         Baligned_free(aGameArrays[i].plValues);
-        aGameArrays[i].plValues = (intptr_t *)Xaligned_alloc(ACTOR_VAR_ALIGNMENT, asize * GAR_ELTSZ);
-        Bmemset(aGameArrays[i].plValues, 0, asize * GAR_ELTSZ);
+        if (asize != 0)
+        {
+            aGameArrays[i].plValues = (intptr_t *)Xaligned_alloc(ACTOR_VAR_ALIGNMENT, asize * GAR_ELTSZ);
+            Bmemset(aGameArrays[i].plValues, 0, asize * GAR_ELTSZ);
+        }
+        else
+            aGameArrays[i].plValues = NULL;
     }
     else
         aGameArrays[i].plValues=(intptr_t *)arrayptr;
diff --git a/polymer/eduke32/source/savegame.c b/polymer/eduke32/source/savegame.c
index 6cbd1a260..5d4524789 100644
--- a/polymer/eduke32/source/savegame.c
+++ b/polymer/eduke32/source/savegame.c
@@ -1215,9 +1215,10 @@ static void sv_makevarspec()
         if (aGameArrays[i].dwFlags & GAMEARRAY_READONLY)
             continue;
 
+        intptr_t * const plValues = aGameArrays[i].plValues;
         svgm_vars[j].flags = 0;
-        svgm_vars[j].ptr = aGameArrays[i].plValues;
-        svgm_vars[j].size = sizeof(aGameArrays[0].plValues[0]);
+        svgm_vars[j].ptr = plValues;
+        svgm_vars[j].size = plValues == NULL ? 0 : sizeof(aGameArrays[0].plValues[0]);
         svgm_vars[j].cnt = aGameArrays[i].size;  // assumed constant throughout demo, i.e. no RESIZEARRAY
         j++;
     }