[mscgen] Declared some variables as pointer to const

Found by Cppcheck (constVariablePointer)

Author: gruenich

deps/libmscgen/gd_lodepng.c

@@ -14,7 +14,7 @@ BGD_DECLARE(void) gdImagePng (gdImagePtr im, FILE * outFile)
     int *pThisRow = *ptpixels++;
     for (x=0;x<im->sx;x++)
     {
-      int thisPixel = *pThisRow++;
+      const int thisPixel = *pThisRow++;
       *pOut++ = gdTrueColorGetRed(thisPixel);
       *pOut++ = gdTrueColorGetGreen(thisPixel);
       *pOut++ = gdTrueColorGetBlue(thisPixel);

deps/libmscgen/mscgen_gd_out.c

@@ -287,7 +287,7 @@ void gdoTextR(struct ADrawTag *ctx,
               unsigned int     y,
               const char      *string)
 {
-    GdoContext *context = getGdoCtx(ctx);
+    const GdoContext *context = getGdoCtx(ctx);
 #ifdef USE_FREETYPE
     int         rect[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
     const char *r;

deps/libmscgen/mscgen_msc.c

@@ -746,7 +746,7 @@ const char *MscGetCurrentArcAttrib(struct MscTag *m, MscAttribType a)
 
 Boolean MscGetOptAsFloat(struct MscTag *m, MscOptType type, float *const f)
 {
-    struct MscOptTag *opt = MscFindOpt(m->optList, type);
+    const struct MscOptTag *opt = MscFindOpt(m->optList, type);
 
     if(opt != NULL)
     {

deps/libmscgen/mscgen_ps_out.c

@@ -268,7 +268,7 @@ void PsTextR(struct ADrawTag *ctx,
               unsigned int     y,
               const char      *string)
 {
-    PsContext *context = getPsCtx(ctx);
+    const PsContext *context = getPsCtx(ctx);
 
     /* Push the string and get its width */
     fprintf(getPsFile(ctx), "(");
@@ -300,7 +300,7 @@ void PsTextL(struct ADrawTag *ctx,
               unsigned int     y,
               const char      *string)
 {
-    PsContext *context = getPsCtx(ctx);
+    const PsContext *context = getPsCtx(ctx);
 
     /* Draw the background box */
     setColour(ctx, context->penBgColour);
@@ -327,7 +327,7 @@ void PsTextC(struct ADrawTag *ctx,
               unsigned int     y,
               const char      *string)
 {
-    PsContext *context = getPsCtx(ctx);
+    const PsContext *context = getPsCtx(ctx);
 
     /* Push the string and get its width */
     fprintf(getPsFile(ctx), "(");

deps/libmscgen/mscgen_svg_out.c

@@ -301,7 +301,7 @@ void SvgTextR(struct ADrawTag *ctx,
               unsigned int     y,
               const char      *string)
 {
-    SvgContext *context = getSvgCtx(ctx);
+    const SvgContext *context = getSvgCtx(ctx);
 
     svgRect(ctx, getSvgBgPen(ctx), x - 2, y - SvgTextHeight(ctx) + 1, x + SvgTextWidth(ctx, string), y - 1);
 
@@ -320,7 +320,7 @@ void SvgTextL(struct ADrawTag *ctx,
               unsigned int     y,
               const char      *string)
 {
-    SvgContext *context = getSvgCtx(ctx);
+    const SvgContext *context = getSvgCtx(ctx);
 
     svgRect(ctx, getSvgBgPen(ctx), x - (SvgTextWidth(ctx, string) + 2), y - SvgTextHeight(ctx) + 1, x, y - 1);
 
@@ -341,7 +341,7 @@ void SvgTextC(struct ADrawTag *ctx,
               unsigned int     y,
               const char      *string)
 {
-    SvgContext  *context = getSvgCtx(ctx);
+    const SvgContext  *context = getSvgCtx(ctx);
     unsigned int hw = SvgTextWidth(ctx, string) / 2;
 
     svgRect(ctx, getSvgBgPen(ctx), x - (hw + 2), y - SvgTextHeight(ctx) + 1, x + hw, y - 1);