Make static C code analysis tool little more happy(#426)

sw_image.c:
	203: The potential null pointer is passed into 'memcpy' function. Inspect the first argument. Check lines: 203, 192.
	368: The null pointer is passed into 'free' function. Inspect the first argument.
	401: Expression '!pic' is always false.
	401: There are two 'if' statements with identical conditional expressions. The first 'if' statement contains function return. This means that the second 'if' statement is senseless. Check lines: 394, 401.
	565: The potential null pointer is passed into 'memcpy' function. Inspect the first argument. Check lines: 565, 564.

sw_model.c:
	215: The 'model' pointer was used unsafely after it was verified against nullptr. Check lines: 210, 215.
	985: The 'header->lumps[12].filelen / sizeof (int)' expression was implicitly cast from 'size_t' type to 'float' type. Consider utilizing an explicit type cast to avoid the loss of a fractional part. An example: double A = (double)(X) / Y;.
	1277: Function 'RE_BeginRegistration' argument 1 names different: declaration 'map' definition 'model'.

sw_surf.c:
	239: There might be dereferencing of a potential null pointer 'sc_base'. Check lines: 239, 236.

sw_main.c:
	1345: The if condition is the same as the previous if condition
	1466: Function 'R_GammaCorrectAndSetPalette' argument 1 names different: declaration 'pal' definition 'palette'
	2063: The 'swap_buffers' pointer in the expression could be nullptr. In such case, resulting value of arithmetic operations on this pointer will be senseless and it should not be used. Check lines: 2063, 2061.

sw_aclip.c:
	180: Variable 'j' is reassigned a value before the old one has been used.

sw_alias.c:
	209: Function 'R_AliasTransformVector' argument 3 names different: declaration 'm' definition 'xf'.

sw_draw.c:
	78: Function 'RE_Draw_CharScaled' argument 3 names different: declaration 'c' definition 'num'.
	149: Function 'RE_Draw_GetPicSize' argument 3 names different: declaration 'name' definition 'pic'.
	173: The scope of the variable 'u' can be reduced.
	267: Function 'RE_Draw_PicScaled' argument 4 names different: declaration 'factor' definition 'scale'.

sw_scan.c
	593: Function 'D_DrawSpansPow2' argument 1 names different: declaration 'pspans' definition 'pspan'.
	745: Function 'D_DrawZSpans' argument 1 names different: declaration 'pspans' definition 'pspan'.

src/client/refresh/soft/header/local.h

@@ -358,8 +358,8 @@ extern float	d_sdivzstepu, d_tdivzstepu;
 extern float	d_sdivzstepv, d_tdivzstepv;
 extern float	d_sdivzorigin, d_tdivzorigin;
 
-void D_DrawSpansPow2(espan_t *pspans, float d_ziorigin, float d_zistepu, float d_zistepv);
+void D_DrawSpansPow2(espan_t *pspan, float d_ziorigin, float d_zistepu, float d_zistepv);
-void D_DrawZSpans(espan_t *pspans, float d_ziorigin, float d_zistepu, float d_zistepv);
+void D_DrawZSpans(espan_t *pspan, float d_ziorigin, float d_zistepu, float d_zistepv);
 void TurbulentPow2(espan_t *pspan, float d_ziorigin, float d_zistepu, float d_zistepv);
 void NonTurbulentPow2(espan_t *pspan, float d_ziorigin, float d_zistepu, float d_zistepv);
 
@@ -557,14 +557,14 @@ void Draw_InitLocal(void);
 void R_InitCaches(void);
 void D_FlushCaches(void);
 
-void	RE_BeginRegistration (char *map);
+void	RE_BeginRegistration (char *model);
-struct model_s  *RE_RegisterModel (char *name);
+struct model_s	*RE_RegisterModel (char *name);
 void	RE_EndRegistration (void);
 
 struct image_s	*RE_Draw_FindPic (char *name);
 
 void	RE_Draw_GetPicSize (int *w, int *h, char *name);
-void	RE_Draw_PicScaled (int x, int y, char *name, float factor);
+void	RE_Draw_PicScaled (int x, int y, char *name, float scale);
 void	RE_Draw_StretchPic (int x, int y, int w, int h, char *name);
 void	RE_Draw_StretchRaw (int x, int y, int w, int h, int cols, int rows, byte *data);
 void	RE_Draw_CharScaled (int x, int y, int c, float scale);

src/client/refresh/soft/sw_aclip.c

@@ -177,7 +177,7 @@ R_AliasClip (const finalvert_t *in, finalvert_t *out, int flag, int count,
 
 	j = count-1;
 	k = 0;
-	for (i=0 ; i<count ; j = i, i++)
+	for (i=0 ; i<count ; i++)
 	{
 		int flags, oldflags;
 
@@ -185,7 +185,10 @@ R_AliasClip (const finalvert_t *in, finalvert_t *out, int flag, int count,
 		flags = in[i].flags & flag;
 
 		if (flags && oldflags)
+		{
+			j = i;
 			continue;
+		}
 		if (oldflags ^ flags)
 		{
 			clip (&in[j], &in[i], &out[k]);
@@ -205,6 +208,7 @@ R_AliasClip (const finalvert_t *in, finalvert_t *out, int flag, int count,
 			out[k] = in[i];
 			k++;
 		}
+		j = i;
 	}
 
 	return k;

src/client/refresh/soft/sw_alias.c

@@ -58,7 +58,7 @@ static const float	r_avertexnormals[NUMVERTEXNORMALS][3] = {
 };
 
 
-static void R_AliasTransformVector(const vec3_t in, vec3_t out, const float m[3][4]);
+static void R_AliasTransformVector(const vec3_t in, vec3_t out, const float xf[3][4]);
 static void R_AliasTransformFinalVerts(const entity_t *currententity, int numpoints, finalvert_t *fv, dtrivertx_t *oldv, dtrivertx_t *newv );
 
 void R_AliasProjectAndClipTestFinalVert(finalvert_t *fv);

src/client/refresh/soft/sw_draw.c

@@ -75,7 +75,7 @@ smoothly scrolled off.
 ================
 */
 void
-RE_Draw_CharScaled(int x, int y, int num, float scale)
+RE_Draw_CharScaled(int x, int y, int c, float scale)
 {
 	pixel_t	*dest;
 	byte	*source;
@@ -87,9 +87,9 @@ RE_Draw_CharScaled(int x, int y, int num, float scale)
 	if (iscale < 1)
 		return;
 
-	num &= 255;
+	c &= 255;
 
-	if (num == 32 || num == 32+128)
+	if (c == 32 || c == 32+128)
 		return;
 
 	if (y <= -8)
@@ -98,8 +98,8 @@ RE_Draw_CharScaled(int x, int y, int num, float scale)
 	if ( ( y + 8 ) > vid.height )	// status text was missing in sw...
 		return;
 
-	row = num>>4;
+	row = c>>4;
-	col = num&15;
+	col = c&15;
 	source = draw_chars->pixels[0] + (row<<10) + (col<<3);
 
 	if (y < 0)
@@ -146,11 +146,11 @@ RE_Draw_GetPicSize
 =============
 */
 void
-RE_Draw_GetPicSize (int *w, int *h, char *pic)
+RE_Draw_GetPicSize (int *w, int *h, char *name)
 {
 	image_t *gl;
 
-	gl = RE_Draw_FindPic (pic);
+	gl = RE_Draw_FindPic (name);
 	if (!gl)
 	{
 		*w = *h = -1;
@@ -170,7 +170,6 @@ RE_Draw_StretchPicImplementation (int x, int y, int w, int h, const image_t *pic
 {
 	pixel_t	*dest;
 	byte	*source;
-	int		v, u;
 	int		height;
 	int		skip;
 
@@ -198,6 +197,8 @@ RE_Draw_StretchPicImplementation (int x, int y, int w, int h, const image_t *pic
 
 	if (w == pic->width)
 	{
+		int v;
+
 		for (v=0 ; v<height ; v++, dest += vid.width)
 		{
 			int sv = (skip + v)*pic->height/h;
@@ -207,9 +208,10 @@ RE_Draw_StretchPicImplementation (int x, int y, int w, int h, const image_t *pic
 	}
 	else
 	{
+		int v;
 		for (v=0 ; v<height ; v++, dest += vid.width)
 		{
-			int f, fstep;
+			int f, fstep, u;
 			int sv = (skip + v)*pic->height/h;
 			source = pic->pixels[0] + sv*pic->width;
 			f = 0;

src/client/refresh/soft/sw_image.c

@@ -190,6 +190,12 @@ R_LoadPic (char *name, byte *pic, int width, int height, imagetype_t type)
 	size = width * height;
 	full_size = R_GetImageMipsSize(size);
 	image->pixels[0] = malloc(full_size);
+	if (!image->pixels[0])
+	{
+		ri.Sys_Error(ERR_FATAL, "%s: Can't allocate image.", __func__);
+		// code never returns after ERR_FATAL
+		return NULL;
+	}
 	image->transparent = false;
 	for (i=0 ; i<size ; i++)
 	{
@@ -363,7 +369,7 @@ R_LoadHiColorImage(char *name, const char* namewe, const char *ext, imagetype_t
 		}
 	}
 
-	if (!pic)
+	if (pic)
 	{
 		free(pic);
 	}
@@ -398,10 +404,7 @@ R_LoadImage(char *name, const char* namewe, const char *ext, imagetype_t type)
 			{
 				free(palette);
 			}
-			if (!pic)
+			free(pic);
-			{
-				free(pic);
-			}
 		}
 		else if (strcmp(ext, "wal") == 0)
 		{
@@ -560,6 +563,8 @@ R_InitImages (void)
 	if ( !table16to8 )
 	{
 		ri.Sys_Error(ERR_FATAL, "%s: Couldn't load pics/16to8.dat", __func__);
+		// code never returns after ERR_FATAL
+		return;
 	}
 	d_16to8table = malloc(0x10000);
 	memcpy(d_16to8table, table16to8, 0x10000);

src/client/refresh/soft/sw_main.c

@@ -1159,7 +1159,7 @@ R_EdgeDrawing (void)
 
 //=======================================================================
 
-static void	R_GammaCorrectAndSetPalette(const unsigned char *pal);
+static void	R_GammaCorrectAndSetPalette(const unsigned char *palette);
 
 /*
 =============
@@ -1267,7 +1267,7 @@ RE_RenderFrame (refdef_t *fd)
 	VectorCopy (fd->vieworg, r_refdef.vieworg);
 	VectorCopy (fd->viewangles, r_refdef.viewangles);
 
-	// compare current possition with old
+	// compare current position with old
 	if (!VectorCompareRound(fd->vieworg, lastvieworg) ||
 	    !VectorCompare(fd->viewangles, lastviewangles))
 	{
@@ -1278,7 +1278,7 @@ RE_RenderFrame (refdef_t *fd)
 		fastmoving = false;
 	}
 
-	// save possition for next check
+	// save position for next check
 	VectorCopy (fd->vieworg, lastvieworg);
 	VectorCopy (fd->viewangles, lastviewangles);
 
@@ -1340,10 +1340,10 @@ RE_RenderFrame (refdef_t *fd)
 		D_WarpScreen ();
 
 	if (r_dspeeds->value)
+	{
 		da_time1 = SDL_GetTicks();
-
-	if (r_dspeeds->value)
 		da_time2 = SDL_GetTicks();
+	}
 
 	// Modify the palette (when taking hit or pickup item) so all colors are modified
 	R_CalcPalette ();
@@ -2172,6 +2172,12 @@ SWimp_CreateRender(void)
 {
 	swap_current = 0;
 	swap_buffers = malloc(vid.height * vid.width * sizeof(pixel_t) * 2);
+	if (!swap_buffers)
+	{
+		ri.Sys_Error(ERR_FATAL, "%s: Can't allocate swapbuffer.", __func__);
+		// code never returns after ERR_FATAL
+		return;
+	}
 	swap_frames[0] = swap_buffers;
 	swap_frames[1] = swap_buffers + vid.height * vid.width * sizeof(pixel_t);
 	vid_buffer = swap_frames[swap_current&1];

src/client/refresh/soft/sw_model.c

@@ -210,6 +210,7 @@ Mod_PointInLeaf (vec3_t p, model_t *model)
 	if (!model || !model->nodes)
 	{
 		ri.Sys_Error(ERR_DROP, "%s: bad model", __func__);
+		return NULL;
 	}
 
 	node = model->nodes;
@@ -982,7 +983,7 @@ Mod_LoadBrushModel(model_t *mod, void *buffer, int modfilelen)
 	int hunkSize = 0;
 	hunkSize += calcLumpHunkSize(&header->lumps[LUMP_VERTEXES], sizeof(dvertex_t), sizeof(mvertex_t), 8);
 	hunkSize += calcLumpHunkSize(&header->lumps[LUMP_EDGES], sizeof(dedge_t), sizeof(medge_t), 13);
-	float surfEdgeCount = header->lumps[LUMP_SURFEDGES].filelen/sizeof(int);
+	float surfEdgeCount = (float)header->lumps[LUMP_SURFEDGES].filelen / sizeof(int);
 	if(surfEdgeCount < MAX_MAP_SURFEDGES) // else it errors out later anyway
 		hunkSize += calcLumpHunkSize(&header->lumps[LUMP_SURFEDGES], sizeof(int), sizeof(int), 24);
 

src/client/refresh/soft/sw_surf.c

@@ -234,6 +234,12 @@ R_InitCaches (void)
 
 	sc_size = size;
 	sc_base = (surfcache_t *)malloc(size);
+	if (!sc_base)
+	{
+		ri.Sys_Error(ERR_FATAL, "%s: Can't allocate cache.", __func__);
+		// code never returns after ERR_FATAL
+		return;
+	}
 	sc_rover = sc_base;
 
 	sc_base->next = NULL;