diff --git a/polymer/eduke32/Makefile b/polymer/eduke32/Makefile
index 6cde0edb6..6d4946aa5 100644
--- a/polymer/eduke32/Makefile
+++ b/polymer/eduke32/Makefile
@@ -205,7 +205,7 @@ ifeq (1,$(RELEASE))
   endif
 endif
 
-mapster32$(EXESUFFIX): $(EDITOROBJS) $(EOBJ)/$(EDITORLIB) $(EOBJ)/$(ENGINELIB) $(JAUDIOLIBDIR)/$(JAUDIOLIB) $(ENETDIR)/$(ENETLIB)
+mapster32$(EXESUFFIX): $(EDITOROBJS) $(EOBJ)/$(EDITORLIB) $(EOBJ)/$(ENGINELIB) $(JAUDIOLIBDIR)/$(JAUDIOLIB)
 	$(LINK_STATUS)
 	if $(CC) $(CFLAGS) $(OURCFLAGS) -o $@ $^ $(LIBS) $(STDCPPLIB) $(MISCLINKOPTS); then $(LINK_OK); else $(LINK_FAILED); fi
 ifeq (1,$(RELEASE))	
diff --git a/polymer/eduke32/build/include/build.h b/polymer/eduke32/build/include/build.h
index 80bdf0f68..d5737579e 100644
--- a/polymer/eduke32/build/include/build.h
+++ b/polymer/eduke32/build/include/build.h
@@ -303,7 +303,7 @@ extern int32_t rendmode;
 EXTERN int32_t h_xsize[MAXTILES], h_ysize[MAXTILES];
 EXTERN int8_t h_xoffs[MAXTILES], h_yoffs[MAXTILES];
 
-extern char *engineerrstr;
+extern const char *engineerrstr;
 extern char noclip;
 
 EXTERN int32_t editorzrange[2];
diff --git a/polymer/eduke32/build/include/compat.h b/polymer/eduke32/build/include/compat.h
index fccecdb9d..680f2e4ad 100644
--- a/polymer/eduke32/build/include/compat.h
+++ b/polymer/eduke32/build/include/compat.h
@@ -549,7 +549,7 @@ int32_t Bcorrectfilename(char *filename, int32_t removefn);
 int32_t Bcanonicalisefilename(char *filename, int32_t removefn);
 char *Bgetsystemdrives(void);
 int32_t Bfilelength(int32_t fd);
-char *Bstrtoken(char *s, char *delim, char **ptrptr, int32_t chop);
+char *Bstrtoken(char *s, const char *delim, char **ptrptr, int32_t chop);
 int32_t Bwildmatch (const char *i, const char *j);
 
 #if !defined(_WIN32)
@@ -566,5 +566,8 @@ char *Bstrupr(char *);
 #define EDUKE32_TMRTIC t[ti++]=getticks()
 #define EDUKE32_TMRPRN do { int ii=0; fprintf(stderr,"%s: ",tmrstr); for (ii=1; ii<ti; ii++) fprintf(stderr,"%d ", t[ii]-t[ii-1]); fprintf(stderr,"\n"); } while (0)
 
+static inline int32_t ARBNDCHK(int32_t i) { return i<0 ? (*(int32_t *)123=234) : i; }
+#define DOUBLEWALL(w) wall[ARBNDCHK(w)]
+
 #endif // __compat_h__
 
diff --git a/polymer/eduke32/build/include/editor.h b/polymer/eduke32/build/include/editor.h
index 9bc23fb95..58615d4b7 100644
--- a/polymer/eduke32/build/include/editor.h
+++ b/polymer/eduke32/build/include/editor.h
@@ -116,7 +116,7 @@ extern const char *SaveBoard(const char *fn, uint32_t flags);
 #define MAXCORRUPTTHINGS 64
 extern int32_t corruptlevel, numcorruptthings, corruptthings[MAXCORRUPTTHINGS];
 extern int32_t autocorruptcheck;
-extern int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing);
+extern int32_t CheckMapCorruption(int32_t printfromlev, uint64_t tryfixing);
 
 extern void showsectordata(int16_t sectnum, int16_t small);
 extern void showwalldata(int16_t wallnum, int16_t small);
diff --git a/polymer/eduke32/build/include/osd.h b/polymer/eduke32/build/include/osd.h
index 815218db8..cebb319a5 100644
--- a/polymer/eduke32/build/include/osd.h
+++ b/polymer/eduke32/build/include/osd.h
@@ -42,8 +42,8 @@ enum cvartype_t
 
 typedef struct
 {
-    char *name;
-    char *helpstr;
+    const char *name;
+    const char *helpstr;
     void *var;
     int32_t type;   // see cvartype_t
     int32_t min;
diff --git a/polymer/eduke32/build/include/polymost.h b/polymer/eduke32/build/include/polymost.h
index 35fc23a3e..1e4526f4a 100644
--- a/polymer/eduke32/build/include/polymost.h
+++ b/polymer/eduke32/build/include/polymost.h
@@ -26,7 +26,7 @@ extern double gcosang, gsinang, gcosang2, gsinang2;
 extern double gchang, gshang, gctang, gstang, gvisibility;
 
 struct glfiltermodes {
-	char *name;
+	const char *name;
 	int32_t min,mag;
 };
 #define numglfiltermodes 6
diff --git a/polymer/eduke32/build/src/baselayer.c b/polymer/eduke32/build/src/baselayer.c
index 48b43ab0a..3fc0f925e 100644
--- a/polymer/eduke32/build/src/baselayer.c
+++ b/polymer/eduke32/build/src/baselayer.c
@@ -147,7 +147,7 @@ static int32_t osdfunc_setrendermode(const osdfuncparm_t *parm)
     int32_t m;
     char *p;
 
-    char *modestrs[] =
+    const char *modestrs[] =
     {
         "classic software", "",
         "", "polygonal OpenGL", "great justice (Polymer)"
diff --git a/polymer/eduke32/build/src/build.c b/polymer/eduke32/build/src/build.c
index 9158c5313..df646745d 100644
--- a/polymer/eduke32/build/src/build.c
+++ b/polymer/eduke32/build/src/build.c
@@ -2077,7 +2077,8 @@ void overheadeditor(void)
                         }
                 }
 
-                Bsprintf(cbuf, "map corrupt (level %d): %d errors", corruptlevel, numcorruptthings);
+                Bsprintf(cbuf, "Map corrupt (level %d): %s%d errors", corruptlevel,
+                         numcorruptthings>=MAXCORRUPTTHINGS ? ">=":"", numcorruptthings);
                 printext16(8,8, editorcolors[13],editorcolors[0],cbuf,0);
             }
 
@@ -5274,7 +5275,11 @@ int32_t getpointhighlight(int32_t xplc, int32_t yplc, int32_t point)
             }
 
             if (dst <= dist)
-                dist = dst, closest = j;
+            {
+                // prefer white walls
+                if (dist<dist || closest==-1 || (wall[j].nextwall>=0)-(wall[closest].nextwall>=0) <= 0)
+                    dist = dst, closest = j;
+            }
         }
 
     if (zoom >= 256)
diff --git a/polymer/eduke32/build/src/cache1d.c b/polymer/eduke32/build/src/cache1d.c
index 7d68973dd..5f945026b 100644
--- a/polymer/eduke32/build/src/cache1d.c
+++ b/polymer/eduke32/build/src/cache1d.c
@@ -69,7 +69,7 @@ static int32_t lockrecip[200];
 
 static char toupperlookup[256];
 
-static void reportandexit(char *errormessage);
+static void reportandexit(const char *errormessage);
 
 extern char pow2char[8];
 
@@ -226,7 +226,7 @@ void agecache(void)
     }
 }
 
-static void reportandexit(char *errormessage)
+static void reportandexit(const char *errormessage)
 {
     int32_t i, j;
 
@@ -841,7 +841,7 @@ void kclose(int32_t handle)
     filehan[handle] = -1;
 }
 
-static int32_t klistaddentry(CACHE1D_FIND_REC **rec, char *name, int32_t type, int32_t source)
+static int32_t klistaddentry(CACHE1D_FIND_REC **rec, const char *name, int32_t type, int32_t source)
 {
     CACHE1D_FIND_REC *r = NULL, *attach = NULL;
 
diff --git a/polymer/eduke32/build/src/compat.c b/polymer/eduke32/build/src/compat.c
index ed1123e8d..427018ca2 100644
--- a/polymer/eduke32/build/src/compat.c
+++ b/polymer/eduke32/build/src/compat.c
@@ -707,7 +707,7 @@ int32_t Bclosedir(BDIR *dir)
 }
 
 
-char *Bstrtoken(char *s, char *delim, char **ptrptr, int32_t chop)
+char *Bstrtoken(char *s, const char *delim, char **ptrptr, int32_t chop)
 {
     char *p, *start;
 
diff --git a/polymer/eduke32/build/src/defs.c b/polymer/eduke32/build/src/defs.c
index 74d882b70..002a3a23a 100644
--- a/polymer/eduke32/build/src/defs.c
+++ b/polymer/eduke32/build/src/defs.c
@@ -82,7 +82,7 @@ enum scripttoken_t
     T_TILEFROMTEXTURE, T_XOFFSET, T_YOFFSET
 };
 
-typedef struct { char *text; int32_t tokenid; } tokenlist;
+typedef struct { const char *text; int32_t tokenid; } tokenlist;
 
 static int32_t getatoken(scriptfile *sf, const tokenlist *tl, int32_t ntokens)
 {
diff --git a/polymer/eduke32/build/src/engine.c b/polymer/eduke32/build/src/engine.c
index ab0c1a302..27bc5e768 100644
--- a/polymer/eduke32/build/src/engine.c
+++ b/polymer/eduke32/build/src/engine.c
@@ -155,7 +155,7 @@ char britable[16][256]; // JBF 20040207: full 8bit precision
 extern char textfont[2048], smalltextfont[2048];
 
 static char kensmessage[128];
-char *engineerrstr = "No error";
+const char *engineerrstr = "No error";
 
 int32_t showfirstwall=0;
 int32_t showheightindicators=2;
@@ -7912,7 +7912,7 @@ int32_t loadmaphack(const char *filename)
         T_LIGHT,
     };
 
-    static struct { char *text; int32_t tokenid; } legaltokens[] =
+    static struct { const char *text; int32_t tokenid; } legaltokens[] =
     {
         { "sprite", T_SPRITE },
         { "angleoff", T_ANGOFF },
@@ -9696,7 +9696,9 @@ int32_t lastwall(int16_t point)
 }
 
 
-//////////
+////////// CLIPMOVE //////////
+
+int32_t clipmoveboxtracenum = 3;
 
 static int32_t clipsprite_try(const spritetype *spr, int32_t xmin, int32_t ymin, int32_t xmax, int32_t ymax)
 {
@@ -9821,17 +9823,24 @@ static int32_t clipsprite_initindex(int32_t curidx, spritetype *curspr, int32_t
     return flipmul;
 }
 
-#define addclipline(dax1, day1, dax2, day2, daoval)      \
-{                                                        \
-    if (clipnum < MAXCLIPNUM) { \
-    clipit[clipnum].x1 = dax1; clipit[clipnum].y1 = day1; \
-    clipit[clipnum].x2 = dax2; clipit[clipnum].y2 = day2; \
-    clipobjectval[clipnum] = daoval;                      \
-    clipnum++;                                            \
-    } else if (!warned) { initprintf("!!clipnum\n"); warned=1; } \
-}                                                        \
- 
-int32_t clipmoveboxtracenum = 3;
+
+static int32_t clipmove_warned=0;
+
+static void addclipline(int32_t dax1, int32_t day1, int32_t dax2, int32_t day2, int32_t daoval)
+{
+    if (clipnum < MAXCLIPNUM)
+    {
+        clipit[clipnum].x1 = dax1; clipit[clipnum].y1 = day1;
+        clipit[clipnum].x2 = dax2; clipit[clipnum].y2 = day2;
+        clipobjectval[clipnum] = daoval;
+        clipnum++;
+    }
+    else if (!clipmove_warned)
+    {
+        initprintf("!!clipnum\n");
+        clipmove_warned = 1;
+    }
+}
 
 //
 // clipmove
@@ -9852,11 +9861,13 @@ int32_t clipmove(vec3_t *vect, int16_t *sectnum,
     int32_t hitwall, cnt, clipyou;
 
     spritetype *curspr=NULL;  // non-NULL when handling sprite with sector-like clipping
-    int32_t curidx=-1, warned=0, clipspritecnt;
+    int32_t curidx=-1, clipspritecnt;
 
     if (((xvect|yvect) == 0) || (*sectnum < 0)) return(0);
     retval = 0;
 
+    clipmove_warned = 0;
+
     oxvect = xvect;
     oyvect = yvect;
 
diff --git a/polymer/eduke32/samples/tests.m32 b/polymer/eduke32/samples/tests.m32
index 5dc737d2e..34f410e75 100644
--- a/polymer/eduke32/samples/tests.m32
+++ b/polymer/eduke32/samples/tests.m32
@@ -42,7 +42,9 @@ defstate arraytest
 ends
 
 defstate itertest
-// iteration and break test
+    var gi gj gk
+    // iteration and break test
+
     for i range 10
     {
         addlogvar i
@@ -82,70 +84,70 @@ define MIN_CONSTANT -2147483648
 defstate consttest
     quote " --- Constants test ---", quote " "
 
-    quote "Shoud be 0:"
+    quote "Should be 0:"
     set i 0, set j TEST_ZERO
     qsprintf TQUOTE "%d %d  %d %d" 0 TEST_ZERO  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be 1:"
+    quote "Should be 1:"
     set i 1, set j TEST_PLUS_ONE
     qsprintf TQUOTE "%d %d  %d %d" 1 TEST_PLUS_ONE  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be -1:"
+    quote "Should be -1:"
     set i -1, set j TEST_MINUS_ONE
     qsprintf TQUOTE "%d %d  %d %d" -1 TEST_MINUS_ONE  i j
     quote TQUOTE, quote " "
 
 
-    quote "Shoud be 32767:"
+    quote "Should be 32767:"
     set i 32767, set j MOST_POSITIVE_DIRECT
     qsprintf TQUOTE "%d %d  %d %d" 32767 MOST_POSITIVE_DIRECT  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be -32768:"
+    quote "Should be -32768:"
     set i -32768, set j MOST_NEGATIVE_DIRECT
     qsprintf TQUOTE "%d %d  %d %d" -32768 MOST_NEGATIVE_DIRECT  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be 32768:"
+    quote "Should be 32768:"
     set i 32768, set j LEAST_POSITIVE_INDIRECT
     qsprintf TQUOTE "%d %d  %d %d" 32768 LEAST_POSITIVE_INDIRECT  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be -32769:"
+    quote "Should be -32769:"
     set i -32769, set j LEAST_NEGATIVE_INDIRECT
     qsprintf TQUOTE "%d %d  %d %d" -32769 LEAST_NEGATIVE_INDIRECT  i j
     quote TQUOTE, quote " "
 
     quote "Hex tests:"
-    quote "Shoud be 32767:"
+    quote "Should be 32767:"
     set i 0x7fff, set j HEX_MOST_POSITIVE_DIRECT
     qsprintf TQUOTE "%d %d  %d %d" 0x7fff HEX_MOST_POSITIVE_DIRECT  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be -32768:"
+    quote "Should be -32768:"
     set i 0xffff8000, set j HEX_MOST_NEGATIVE_DIRECT
     qsprintf TQUOTE "%d %d  %d %d" 0xffff8000 HEX_MOST_NEGATIVE_DIRECT  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be 32768:"
+    quote "Should be 32768:"
     set i 0x8000, set j HEX_LEAST_POSITIVE_INDIRECT
     qsprintf TQUOTE "%d %d  %d %d" 0x8000 HEX_LEAST_POSITIVE_INDIRECT  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be -32769:"
+    quote "Should be -32769:"
     set i 0xffff7fff, set j HEX_LEAST_NEGATIVE_INDIRECT
     qsprintf TQUOTE "%d %d  %d %d" 0xffff7fff HEX_LEAST_NEGATIVE_INDIRECT  i j
     quote TQUOTE, quote " "
 
     quote "min/max tests:"
-    quote "Shoud be 2147483647:"
+    quote "Should be 2147483647:"
     set i 2147483647, set j MAX_CONSTANT
     qsprintf TQUOTE "%d %d  %d %d" 2147483647 MAX_CONSTANT  i j
     quote TQUOTE, quote " "
 
-    quote "Shoud be -2147483648:"
+    quote "Should be -2147483648:"
     set i -2147483648, set j MIN_CONSTANT
     qsprintf TQUOTE "%d %d  %d %d" -2147483648 MIN_CONSTANT  i j
     quote TQUOTE, quote " "
diff --git a/polymer/eduke32/samples/tiles.cfg b/polymer/eduke32/samples/tiles.cfg
index 235194a33..a69fbeda7 100644
--- a/polymer/eduke32/samples/tiles.cfg
+++ b/polymer/eduke32/samples/tiles.cfg
@@ -3,8 +3,6 @@
 
 #include "names.h"
 
-// tilegroup "All named" with the hotkey "Y" is constructed automatically
-
 tilegroup "Actors"
 {
 	hotkey "A"
diff --git a/polymer/eduke32/source/astub.c b/polymer/eduke32/source/astub.c
index 95b3b9a8c..7c942ebdd 100644
--- a/polymer/eduke32/source/astub.c
+++ b/polymer/eduke32/source/astub.c
@@ -3788,7 +3788,7 @@ static inline void getnumber_doint64(int64_t *ptr, int32_t num)
     *ptr = (int64_t) num;
 }
 
-void getnumberptr256(char *namestart, void *num, int32_t bytes, int32_t maxnumber, char sign, void *(func)(int32_t))
+static void getnumberptr256(const char *namestart, void *num, int32_t bytes, int32_t maxnumber, char sign, void *(func)(int32_t))
 {
     char buffer[80], ch;
     int32_t n, danum = 0, oldnum;
@@ -7090,8 +7090,8 @@ static void Keys2d(void)
                 }
                 else x=editorgridextent+1;
 
-                printmessage16("%s Corrupt %s %d%s", tsign<0?"<":">", secwalspr[j], i,
-                               (x==editorgridextent+1) ? " (outside grid)" : (wrap ? " (wrap)" : ""));
+                printmessage16("#%d: %s Corrupt %s %d%s", curcorruptthing+1, tsign<0?"<":">", secwalspr[j],
+                               i, (x==editorgridextent+1) ? " (outside grid)" : (wrap ? " (wrap)" : ""));
             }
         }
         else if (wallsprite==0)
@@ -7346,7 +7346,7 @@ void ExtPreSaveMap(void)
 
 static void G_ShowParameterHelp(void)
 {
-    char *s = "Usage: mapster32 [OPTIONS] [FILE]\n\n"
+    const char *s = "Usage: mapster32 [OPTIONS] [FILE]\n\n"
               "-gFILE, -grp FILE\tUse extra group file FILE\n"
               "-hFILE\t\tUse definitions file FILE\n"
               "-jDIR, -game_dir DIR\n\t\tAdds DIR to the file path stack\n"
@@ -7655,6 +7655,11 @@ int32_t ExtPreInit(int32_t argc,const char **argv)
     return 0;
 }
 
+static int32_t atoi_safe(const char *str)
+{
+    return (int32_t)strtol(str, NULL, 10);
+}
+
 static int32_t osdcmd_quit(const osdfuncparm_t *parm)
 {
     UNREFERENCED_PARAMETER(parm);
@@ -7784,7 +7789,7 @@ static int32_t osdcmd_vars_pk(const osdfuncparm_t *parm)
             OSD_Printf("Turning acceleration+declaration is %d\n", pk_turnaccel);
         else
         {
-            pk_turnaccel = atoi(parm->parms[0]);
+            pk_turnaccel = atoi_safe(parm->parms[0]);
             pk_turnaccel = pk_turnaccel<=pk_turndecel ? (pk_turndecel+1):pk_turnaccel;
             pk_turnaccel = pk_turnaccel>256 ? 256:pk_turnaccel;
         }
@@ -7795,7 +7800,7 @@ static int32_t osdcmd_vars_pk(const osdfuncparm_t *parm)
             OSD_Printf("Turning deceleration is %d\n", pk_turndecel);
         else
         {
-            pk_turndecel = atoi(parm->parms[0]);
+            pk_turndecel = atoi_safe(parm->parms[0]);
             pk_turndecel = pk_turndecel<=0 ? 1:pk_turndecel;
             pk_turndecel = pk_turndecel>=pk_turnaccel ? (pk_turnaccel-1):pk_turndecel;
             pk_turndecel = pk_turndecel>128 ? 128:pk_turndecel;
@@ -7810,7 +7815,7 @@ static int32_t osdcmd_vars_pk(const osdfuncparm_t *parm)
     {
         if (parm->numparms==1)
         {
-            pk_uedaccel = atoi(parm->parms[0]);
+            pk_uedaccel = atoi_safe(parm->parms[0]);
             pk_uedaccel = pk_uedaccel<0 ? 0:pk_uedaccel;
             pk_uedaccel = pk_uedaccel>5 ? 5:pk_uedaccel;
         }
@@ -7843,7 +7848,7 @@ static int32_t osdcmd_vars_pk(const osdfuncparm_t *parm)
         static const char *how[3] = {"none", "two-sided walls only", "all"};
 
         if (parm->numparms == 1)
-            showheightindicators = clamp(atoi(parm->parms[0]), 0, 2);
+            showheightindicators = clamp(atoi_safe(parm->parms[0]), 0, 2);
 
         if (parm->numparms <= 1)
             OSD_Printf("height indicators: %s\n", how[showheightindicators]);
@@ -7855,7 +7860,7 @@ static int32_t osdcmd_vars_pk(const osdfuncparm_t *parm)
         static const char *how[3] = {"none", "current sector only", "all"};
 
         if (parm->numparms == 1)
-            showambiencesounds = clamp(atoi(parm->parms[0]), 0, 2);
+            showambiencesounds = clamp(atoi_safe(parm->parms[0]), 0, 2);
 
         if (parm->numparms <= 1)
             OSD_Printf("ambience sound circles: %s\n", how[showambiencesounds]);
@@ -7864,7 +7869,9 @@ static int32_t osdcmd_vars_pk(const osdfuncparm_t *parm)
     }
     else if (!Bstrcasecmp(parm->name, "corruptcheck"))
     {
-        if (parm->numparms == 1)
+        int32_t tryfix = parm->numparms>=1 && !Bstrcasecmp(parm->parms[0], "tryfix");
+
+        if (parm->numparms == 1 || tryfix)
         {
             if (!Bstrcasecmp(parm->parms[0], "now"))
             {
@@ -7872,14 +7879,47 @@ static int32_t osdcmd_vars_pk(const osdfuncparm_t *parm)
                     OSD_Printf("All OK.\n");
                 return OSDCMD_OK;
             }
-            else if (!Bstrcasecmp(parm->parms[0], "tryfix"))
+            else if (tryfix)
             {
-                CheckMapCorruption(3, 1);
+                uint64_t whicherrs = parm->numparms==1 ? ULONG_LONG_MAX : 0;
+
+                if (whicherrs==0)
+                {
+                    int32_t i, n, m;
+                    char *endptr;
+                    for (i=1; i<parm->numparms; i++)
+                    {
+                        n = (int32_t)Bstrtol(parm->parms[i], &endptr, 10);
+                        if (endptr != parm->parms[i])
+                        {
+                            if (*endptr=='-')
+                            {
+                                m = (int32_t)Bstrtol(endptr+1, NULL, 10);
+                                if (n>=1 && n<=m && m<=MAXCORRUPTTHINGS)
+                                {
+                                    uint64_t mask = ULONG_LONG_MAX;
+                                    m = m-n+1;
+                                    mask >>= (MAXCORRUPTTHINGS-m);
+                                    mask <<= (n-1);
+
+                                    whicherrs |= mask;
+                                }
+                            }
+                            else
+                            {
+                                if (n>=1 && n<=MAXCORRUPTTHINGS)
+                                    whicherrs |= (1ull<<(n-1));
+                            }
+                        }
+                    }
+                }
+
+                CheckMapCorruption(3, whicherrs);
                 return OSDCMD_OK;
             }
             else if (isdigit(parm->parms[0][0]))
             {
-                autocorruptcheck = clamp(atoi(parm->parms[0]), 0, 3600);
+                autocorruptcheck = clamp(atoi_safe(parm->parms[0]), 0, 3600);
                 corruptchecktimer = totalclock + 120*autocorruptcheck;
             }
         }
@@ -7891,7 +7931,7 @@ static int32_t osdcmd_vars_pk(const osdfuncparm_t *parm)
             else
                 OSD_Printf("auto corruption check: off\n");
         }
-        else
+        else if (!tryfix)
             return OSDCMD_SHOWHELP;
     }
 
@@ -7906,7 +7946,7 @@ static int32_t osdcmd_tint(const osdfuncparm_t *parm)
 
     if (parm->numparms==1)
     {
-        i = atoi(parm->parms[0]);
+        i = atoi_safe(parm->parms[0]);
         if (i>=0 && i<MAXPALOOKUPS-RESERVEDPALS)
         {
             p = &hictinting[i];
@@ -7922,15 +7962,15 @@ static int32_t osdcmd_tint(const osdfuncparm_t *parm)
     }
     else if (parm->numparms>=2)
     {
-        i = atoi(parm->parms[0]);
+        i = atoi_safe(parm->parms[0]);
         if (i<0 || i>=MAXPALOOKUPS-RESERVEDPALS)
             return OSDCMD_SHOWHELP;
 
         p = &hictinting[i];
-        p->r = atoi(parm->parms[1]);
-        p->g = (parm->numparms>=3) ? atoi(parm->parms[2]) : 255;
-        p->b = (parm->numparms>=4) ? atoi(parm->parms[3]) : 255;
-        p->f = (parm->numparms>=5) ? atoi(parm->parms[4])&HICEFFECTMASK : 0;
+        p->r = atoi_safe(parm->parms[1]);
+        p->g = (parm->numparms>=3) ? atoi_safe(parm->parms[2]) : 255;
+        p->b = (parm->numparms>=4) ? atoi_safe(parm->parms[3]) : 255;
+        p->f = (parm->numparms>=5) ? atoi_safe(parm->parms[4])&HICEFFECTMASK : 0;
     }
     return OSDCMD_OK;
 }
@@ -7965,7 +8005,7 @@ static int32_t osdcmd_disasm(const osdfuncparm_t *parm)
     if (!isdigit(parm->parms[1][0]))
         return OSDCMD_SHOWHELP;
 
-    i=atoi(parm->parms[1]);
+    i=atoi_safe(parm->parms[1]);
 
     if (parm->parms[0][0]=='s')
     {
@@ -8122,7 +8162,7 @@ static int32_t osdcmd_endisableevent(const osdfuncparm_t *parm)
 
         if (isdigit(parm->parms[i][0]))
         {
-            j = atoi(parm->parms[i]);
+            j = atoi_safe(parm->parms[i]);
             Bsprintf(buf2, "event %d", j);
         }
         else if (!Bstrncmp(parm->parms[i], "EVENT_", 6))
@@ -8349,12 +8389,12 @@ enum
 
 typedef struct
 {
-    char *text;
+    const char *text;
     int32_t tokenid;
 }
 tokenlist;
 
-static int32_t getatoken(scriptfile *sf, tokenlist *tl, int32_t ntokens)
+static int32_t getatoken(scriptfile *sf, const tokenlist *tl, int32_t ntokens)
 {
     char *tok;
     int32_t i;
@@ -8466,7 +8506,7 @@ int32_t parsegroupfiles(scriptfile *script)
     return 0;
 }
 
-int32_t loadgroupfiles(char *fn)
+int32_t loadgroupfiles(const char *fn)
 {
     scriptfile *script;
 
@@ -10038,48 +10078,57 @@ void ExtCheckKeys(void)
 //// port of a.m32's corruptchk ////
 // returns value from 0 (all OK) to 5 (panic!)
 #define CCHK_PANIC OSDTEXT_DARKRED "PANIC!!!^O "
-#define CCHKPREF OSDTEXT_RED "* ^O"
+//#define CCHKPREF OSDTEXT_RED "^O"
 #define CCHK_CORRECTED OSDTEXT_GREEN " -> "
 
 #define CORRUPTCHK_PRINT(errlev, what, fmt, ...) do  \
 { \
     bad = max(bad, errlev); \
-    if (numcorruptthings<MAXCORRUPTTHINGS) \
-        corruptthings[numcorruptthings++] = what;   \
+    if (numcorruptthings>=MAXCORRUPTTHINGS) \
+        goto too_many_errors; \
+    corruptthings[numcorruptthings++] = what; \
     if (errlev >= printfromlev) \
-        OSD_Printf(CCHKPREF fmt "\n", ## __VA_ARGS__); \
+        OSD_Printf("#%d: " fmt "\n", numcorruptthings, ## __VA_ARGS__); \
 } while (0)
 
+static int32_t walls_are_consistent(int32_t nw, int32_t j)
+{
+    return (wall[j].x==POINT2(nw).x && wall[j].y==POINT2(nw).y
+                && POINT2(j).x==wall[nw].x && POINT2(j).y==wall[nw].y);
+}
+
 static void suggest_nextsector_correction(int32_t nw, int32_t j)
 {
     if (nw>=0 && nw<numwalls)
     {
         // maybe nextwall is right?
-        if (wall[nw].nextwall==j && wall[j].x==POINT2(nw).x && wall[j].y==POINT2(nw).y)
-            OSD_Printf("    suggest setting wall[%d].nextsector to %d\n", j, sectorofwall_noquick(nw));
+        if (wall[nw].nextwall==j && walls_are_consistent(nw, j))
+            OSD_Printf("   suggest setting wall[%d].nextsector to %d\n",
+                       j, sectorofwall_noquick(nw));
     }
 }
 
 static void do_nextsector_correction(int32_t nw, int32_t j)
 {
     if (nw>=0 && nw<numwalls)
-        if (wall[nw].nextwall==j && wall[j].x==POINT2(nw).x && wall[j].y==POINT2(nw).y)
+        if (wall[nw].nextwall==j && walls_are_consistent(nw, j))
         {
             int32_t newns = sectorofwall_noquick(nw);
             wall[j].nextsector = newns;
-            OSD_Printf(CCHK_CORRECTED "auto-correction: set wall[%d].nextsector=%d\n", j, newns);
+            OSD_Printf(CCHK_CORRECTED "auto-correction: set wall[%d].nextsector=%d\n",
+                       j, newns);
         }
 }
 
-int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing)
+int32_t CheckMapCorruption(int32_t printfromlev, uint64_t tryfixing)
 {
     int32_t i, j, w0, numw, endwall, ns, nw;
     int32_t ewall=0;  // expected wall index
 
     int32_t errlevel=0, bad=0;
 
-    uint8_t *seen_nextwalls;
-    int16_t *lastnextwallsource;
+    uint8_t *seen_nextwalls = NULL;
+    int16_t *lastnextwallsource = NULL;
 
     numcorruptthings = 0;
 
@@ -10124,9 +10173,9 @@ int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing)
         if (endwall > numwalls)
             CORRUPTCHK_PRINT(4, CORRUPT_SECTOR|i, "SECTOR[%d]: wallptr+wallnum=%d out of range: numwalls=%d", i, endwall, numwalls);
 
-        if (bad)
-            errlevel = max(errlevel, bad);
-        else
+        errlevel = max(errlevel, bad);
+
+        if (bad<4)
         {
             endwall--;
 
@@ -10162,11 +10211,15 @@ int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing)
                 {
                     if (!bad)
                     {
+                        int32_t onumct = numcorruptthings;
                         CORRUPTCHK_PRINT(4, CORRUPT_WALL|j, "WALL[%d].NEXTSECTOR is its own sector", j);
-                        if (tryfixing)
-                            do_nextsector_correction(nw, j);
-                        else if (4>=printfromlev)
-                            suggest_nextsector_correction(nw, j);
+                        if (onumct < MAXCORRUPTTHINGS)
+                        {
+                            if (tryfixing & (1ull<<onumct))
+                                do_nextsector_correction(nw, j);
+                            else if (4>=printfromlev)
+                                suggest_nextsector_correction(nw, j);
+                        }
                     }
                 }
 
@@ -10175,15 +10228,16 @@ int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing)
                     if (seen_nextwalls[nw>>3]&(1<<(nw&7)))
                     {
                         int16_t nwnw, lnws;
+                        int32_t onumct = numcorruptthings;
 
                         lnws = lastnextwallsource[nw];
                         CORRUPTCHK_PRINT(3, CORRUPT_WALL|j, "WALL[%d].NEXTWALL=%d already referenced from wall %d",
                                          j, nw, lnws);
                         nwnw = wall[nw].nextwall;
-                        if (nwnw==j || nwnw==lnws)
+                        if (onumct < MAXCORRUPTTHINGS && (nwnw==j || nwnw==lnws))
                         {
                             int32_t walltoclear = nwnw==j ? lnws : j;
-                            if (tryfixing)
+                            if (tryfixing & (1ull<<onumct))
                             {
                                 wall[walltoclear].nextsector = wall[walltoclear].nextwall = -1;
                                 OSD_Printf(CCHK_CORRECTED "auto-correction: cleared wall %d's nextwall and nextsector tags to -1\n",
@@ -10203,14 +10257,18 @@ int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing)
 
                 if (bad<4)
                 {
+                    int32_t onumct = numcorruptthings;
                     if ((ns^nw)<0)
                     {
                         CORRUPTCHK_PRINT(4, CORRUPT_WALL|j, "WALL[%d].NEXTSECTOR=%d and .NEXTWALL=%d inconsistent:"
                                          " missing one next pointer", j, ns, nw);
-                        if (tryfixing)
-                            do_nextsector_correction(nw, j);
-                        else if (4>=printfromlev)
-                            suggest_nextsector_correction(nw, j);
+                        if (onumct < MAXCORRUPTTHINGS)
+                        {
+                            if (tryfixing & (1ull<<onumct))
+                                do_nextsector_correction(nw, j);
+                            else if (4>=printfromlev)
+                                suggest_nextsector_correction(nw, j);
+                        }
                     }
                     else if (ns>=0)
                     {
@@ -10218,13 +10276,16 @@ int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing)
                         {
                             CORRUPTCHK_PRINT(4, CORRUPT_WALL|j, "WALL[%d].NEXTWALL=%d out of .NEXTSECTOR=%d's bounds",
                                              j, nw, ns);
-                            if (tryfixing)
-                                do_nextsector_correction(nw, j);
-                            else if (4 >= printfromlev)
+                            if (onumct < MAXCORRUPTTHINGS)
                             {
-                                OSD_Printf("    sector %d's walls: [%d .. %d]\n", ns, sector[ns].wallptr,
-                                           sector[ns].wallptr+sector[ns].wallnum-1);
-                                suggest_nextsector_correction(nw, j);
+                                if (tryfixing & (1ull<<onumct))
+                                    do_nextsector_correction(nw, j);
+                                else if (4 >= printfromlev)
+                                {
+                                    OSD_Printf("    sector %d's walls: [%d .. %d]\n", ns,
+                                               sector[ns].wallptr, sector[ns].wallptr+sector[ns].wallnum-1);
+                                    suggest_nextsector_correction(nw, j);
+                                }
                             }
                         }
                     }
@@ -10251,6 +10312,13 @@ int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing)
         }
     }
 
+    if (0)
+    {
+too_many_errors:
+        if (printfromlev<=errlevel)
+            OSD_Printf("!! too many errors, stopping. !!\n");
+    }
+
     errlevel = max(errlevel, bad);
 
     if (errlevel)
@@ -10259,8 +10327,11 @@ int32_t CheckMapCorruption(int32_t printfromlev, int32_t tryfixing)
             OSD_Printf("-- corruption level: %d\n", errlevel);
     }
 
-    Bfree(seen_nextwalls);
-    Bfree(lastnextwallsource);
+    if (seen_nextwalls)
+    {
+        Bfree(seen_nextwalls);
+        Bfree(lastnextwallsource);
+    }
 
     corruptlevel = errlevel;
 
@@ -10506,7 +10577,7 @@ static void EditSectorData(int16_t sectnum)
                 break;
             }
         }
-        if (col == 2)
+        else if (col == 2)
         {
             switch (row)
             {
@@ -10606,10 +10677,10 @@ static void EditWallData(int16_t wallnum)
             {
                 Bsprintf(med_edittext,"Wall %d X Repeat: ",wallnum);
                 printmessage16("%s", med_edittext);
-                wall[wallnum].xrepeat = (char)getnumber16(med_edittext,(int32_t)wall[wallnum].xrepeat,256L,0);
+                wall[wallnum].xrepeat = (char)getnumber16(med_edittext,(int32_t)wall[wallnum].xrepeat,255,0);
                 Bsprintf(med_edittext,"Wall %d Y Repeat: ",wallnum);
                 printmessage16("%s", med_edittext);
-                wall[wallnum].yrepeat = (char)getnumber16(med_edittext,(int32_t)wall[wallnum].yrepeat,256L,0);
+                wall[wallnum].yrepeat = (char)getnumber16(med_edittext,(int32_t)wall[wallnum].yrepeat,255,0);
             }
             break;
         case 4:
@@ -10618,10 +10689,10 @@ static void EditWallData(int16_t wallnum)
             {
                 Bsprintf(med_edittext,"Wall %d X Pan: ",wallnum);
                 printmessage16("%s", med_edittext);
-                wall[wallnum].xpanning = (char)getnumber16(med_edittext,(int32_t)wall[wallnum].xpanning,256L,0);
+                wall[wallnum].xpanning = (char)getnumber16(med_edittext,(int32_t)wall[wallnum].xpanning,255,0);
                 Bsprintf(med_edittext,"Wall %d Y Pan: ",wallnum);
                 printmessage16("%s", med_edittext);
-                wall[wallnum].ypanning = (char)getnumber16(med_edittext,(int32_t)wall[wallnum].ypanning,256L,0);
+                wall[wallnum].ypanning = (char)getnumber16(med_edittext,(int32_t)wall[wallnum].ypanning,255,0);
             }
             break;
         case 5:
@@ -10889,7 +10960,7 @@ static void GenericSpriteSearch()
     int32_t rowmax[3]= {6,5,6}, dispwidth[3] = {24,24,28};
     int32_t xpos[3] = {8,200,400}, ypos = ydim-STATUS2DSIZ+48;
 
-    static char *labels[7][3] =
+    static const char *labels[7][3] =
     {
         {"X-coordinate", "Flags (hex)", "Angle (2048 degrees)"},
         {"Y-coordinate", "Shade",       "X-Velocity"},
diff --git a/polymer/eduke32/source/m32def.c b/polymer/eduke32/source/m32def.c
index 2179f1af9..231118a95 100644
--- a/polymer/eduke32/source/m32def.c
+++ b/polymer/eduke32/source/m32def.c
@@ -909,6 +909,26 @@ static int32_t GetGamearrayID(const char *szGameLabel, int32_t searchlocals)
 #define GV_WRITABLE GAMEVAR_READONLY
 #define GV_SIMPLE GAMEVAR_SPECIAL
 
+static int32_t parse_integer_literal(int32_t *num)
+{
+    if (tolower(textptr[1])=='x')
+        sscanf(textptr+2, "%" SCNx32, num);
+    else
+    {
+        long lnum;
+        errno = 0;
+        lnum = strtol(textptr, NULL, 10);
+        if (errno || (sizeof(long)>4 && (lnum<INT_MIN || lnum>INT_MAX)))
+        {
+            C_CUSTOMERROR("integer literal exceeds bitwidth.");
+            return 1;
+        }
+        *num = (int32_t)lnum;
+    }
+
+    return 0;
+}
+
 static void C_GetNextVarType(int32_t type)
 {
     int32_t i, id=0, flags=0, num, indirect=0; //, thenum;
@@ -940,13 +960,10 @@ static void C_GetNextVarType(int32_t type)
 //        if (!(g_numCompilerErrors || g_numCompilerWarnings) && g_scriptDebug)
 //            initprintf("%s:%d: debug: accepted constant %d in place of gamevar.\n",g_szScriptFileName,g_lineNumber,atol(textptr));
 
-        if (tolower(textptr[1])=='x')
-            sscanf(textptr+2, "%" SCNx32, &num);
-        else
-            num = atoi(textptr);
+        parse_integer_literal(&num);
 //thenum=num;
         if (type==GV_SIMPLE && (num<0 || num>=65536))
-            C_CUSTOMERROR("array index %d out of bounds. (max: 65535)",  num);
+            C_CUSTOMERROR("array index %d out of bounds. (max: 65535)", num);
 
         if (g_numCompilerErrors==0 && type!=GV_SIMPLE && num != (int16_t)num)
         {
@@ -1442,10 +1459,7 @@ static int32_t C_GetNextValue(int32_t type)
 //    if (!(g_numCompilerErrors || g_numCompilerWarnings) && g_scriptDebug > 1)
 //        initprintf("%s:%d: debug: accepted constant %d.\n",g_szScriptFileName,g_lineNumber,atol(textptr));
 
-    if (tolower(textptr[1])=='x')
-        sscanf(textptr+2,"%" SCNx32 "",g_scriptPtr);
-    else
-        *g_scriptPtr = atol(textptr);
+    parse_integer_literal(g_scriptPtr);
 
     g_scriptPtr++;
 
diff --git a/polymer/eduke32/source/m32def.h b/polymer/eduke32/source/m32def.h
index 1a3c0b816..9da93f7df 100644
--- a/polymer/eduke32/source/m32def.h
+++ b/polymer/eduke32/source/m32def.h
@@ -70,7 +70,7 @@ extern int32_t g_stateCount;
 
 typedef struct
 {
-    char *name;
+    const char *name;
     int16_t lId;
     int16_t flags;  // 1: read-only
     int32_t min, max;
@@ -82,7 +82,8 @@ extern const memberlabel_t SpriteLabels[];
 
 
 typedef struct {
-    char* token; int32_t val;
+    const char* token;
+    int32_t val;
 } tokenmap_t;
 
 extern const tokenmap_t iter_tokens[];
diff --git a/polymer/eduke32/source/m32exec.c b/polymer/eduke32/source/m32exec.c
index 472583b42..7989b7359 100644
--- a/polymer/eduke32/source/m32exec.c
+++ b/polymer/eduke32/source/m32exec.c
@@ -440,9 +440,11 @@ skip_check:
                         //AddLog("Done Executing Case");
                         bMatched=1;
                     }
+
                     if (right-left < 0)
                         break;
                 }
+
                 if (!bMatched)
                 {
                     if (*lpDefault >= 0)
diff --git a/polymer/eduke32/source/mapster32.h b/polymer/eduke32/source/mapster32.h
index 33d9c2637..7695f9c09 100644
--- a/polymer/eduke32/source/mapster32.h
+++ b/polymer/eduke32/source/mapster32.h
@@ -26,7 +26,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
 // #define VULGARITY
 
-char *defsfilename = "duke3d.def";
+const char *defsfilename = "duke3d.def";
 
 extern char keystatus[];
 extern int16_t defaultspritecstat;
diff --git a/polymer/eduke32/source/savegame.c b/polymer/eduke32/source/savegame.c
index 63f247fa2..d55248c87 100644
--- a/polymer/eduke32/source/savegame.c
+++ b/polymer/eduke32/source/savegame.c
@@ -937,7 +937,7 @@ static uint8_t savegame_comprthres;
 // 64
 #define DS_LOADFN 128  // .ptr is function that is run when loading
 #define DS_SAVEFN 256  // .ptr is function that is run when saving
-#define DS_NOCHK 1024  // don't check for diffs (and don't write out in dump) since assumend constant throughout demo
+#define DS_NOCHK 1024  // don't check for diffs (and don't write out in dump) since assumed constant throughout demo
 #define DS_END (0x70000000)
 
 static int32_t ds_getcnt(const dataspec_t *sp)
diff --git a/polymer/eduke32/source/sdlmusic.c b/polymer/eduke32/source/sdlmusic.c
index 04abe0a33..aa3e44b5d 100644
--- a/polymer/eduke32/source/sdlmusic.c
+++ b/polymer/eduke32/source/sdlmusic.c
@@ -226,7 +226,7 @@ fallback:
     }
 
     {
-        static char *s[] = { "/etc/timidity.cfg", "/etc/timidity/timidity.cfg", "/etc/timidity/freepats.cfg" };
+        static const char *s[] = { "/etc/timidity.cfg", "/etc/timidity/timidity.cfg", "/etc/timidity/freepats.cfg" };
         FILE *fp;
         int32_t i;