SDL_image: fixed several -Wzero-as-null-pointer-constant warnings from gcc-15

From 9c85c887b7a3f273db65cb79fb2ae597c21918ac Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Mon, 17 Nov 2025 22:25:24 +0300
Subject: [PATCH] fixed several -Wzero-as-null-pointer-constant warnings from
 gcc-15

---
 src/nanosvg.h     | 28 ++++++++++++++--------------
 src/nanosvgrast.h |  2 +-
 src/stb_image.h   |  8 ++++----
 3 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/src/nanosvg.h b/src/nanosvg.h
index 1049fe4e6..63b1c5efc 100644
--- a/src/nanosvg.h
+++ b/src/nanosvg.h
@@ -229,7 +229,7 @@ NSVG_EXPORT void nsvgDelete(NSVGimage* image);
 
 static int nsvg__isspace(char c)
 {
-	return strchr(" \t\n\v\f\r", c) != 0;
+	return strchr(" \t\n\v\f\r", c) != NULL;
 }
 
 static int nsvg__isdigit(char c)
@@ -325,8 +325,8 @@ static void nsvg__parseElement(char* s,
 	}
 
 	// List terminator
-	attr[nattr++] = 0;
-	attr[nattr++] = 0;
+	attr[nattr++] = NULL;
+	attr[nattr++] = NULL;
 
 	// Call callbacks.
 	if (start && startelCb)
@@ -2313,8 +2313,8 @@ static void nsvg__parsePath(NSVGparser* p, const char** attr)
 		} else {
 			tmp[0] = attr[i];
 			tmp[1] = attr[i + 1];
-			tmp[2] = 0;
-			tmp[3] = 0;
+			tmp[2] = NULL;
+			tmp[3] = NULL;
 			nsvg__parseAttribs(p, tmp);
 		}
 	}
@@ -2649,27 +2649,27 @@ static void nsvg__parseSVG(NSVGparser* p, const char** attr)
 				s = nsvg__parseNumber(s, buf, 64);
 				p->viewHeight = nsvg__atof(buf);
 			} else if (strcmp(attr[i], "preserveAspectRatio") == 0) {
-				if (strstr(attr[i + 1], "none") != 0) {
+				if (strstr(attr[i + 1], "none") != NULL) {
 					// No uniform scaling
 					p->alignType = NSVG_ALIGN_NONE;
 				} else {
 					// Parse X align
-					if (strstr(attr[i + 1], "xMin") != 0)
+					if (strstr(attr[i + 1], "xMin") != NULL)
 						p->alignX = NSVG_ALIGN_MIN;
-					else if (strstr(attr[i + 1], "xMid") != 0)
+					else if (strstr(attr[i + 1], "xMid") != NULL)
 						p->alignX = NSVG_ALIGN_MID;
-					else if (strstr(attr[i + 1], "xMax") != 0)
+					else if (strstr(attr[i + 1], "xMax") != NULL)
 						p->alignX = NSVG_ALIGN_MAX;
 					// Parse X align
-					if (strstr(attr[i + 1], "yMin") != 0)
+					if (strstr(attr[i + 1], "yMin") != NULL)
 						p->alignY = NSVG_ALIGN_MIN;
-					else if (strstr(attr[i + 1], "yMid") != 0)
+					else if (strstr(attr[i + 1], "yMid") != NULL)
 						p->alignY = NSVG_ALIGN_MID;
-					else if (strstr(attr[i + 1], "yMax") != 0)
+					else if (strstr(attr[i + 1], "yMax") != NULL)
 						p->alignY = NSVG_ALIGN_MAX;
 					// Parse meet/slice
 					p->alignType = NSVG_ALIGN_MEET;
-					if (strstr(attr[i + 1], "slice") != 0)
+					if (strstr(attr[i + 1], "slice") != NULL)
 						p->alignType = NSVG_ALIGN_SLICE;
 				}
 			}
@@ -3094,7 +3094,7 @@ static void nsvg__createGradients(NSVGparser* p)
 NSVG_EXPORT NSVGimage* nsvgParse(char* input, const char* units, float dpi)
 {
 	NSVGparser* p;
-	NSVGimage* ret = 0;
+	NSVGimage* ret = NULL;
 
 	p = nsvg__createParser();
 	if (p == NULL) {
diff --git a/src/nanosvgrast.h b/src/nanosvgrast.h
index b0368e753..9dca93fca 100644
--- a/src/nanosvgrast.h
+++ b/src/nanosvgrast.h
@@ -886,7 +886,7 @@ static NSVGactiveEdge* nsvg__addActive(NSVGrasterizer* r, NSVGedge* e, float sta
 	z->x = (int)nsvg__roundf(NSVG__FIX * (e->x0 + dxdy * (startPoint - e->y0)));
 //	z->x -= off_x * FIX;
 	z->ey = e->y1;
-	z->next = 0;
+	z->next = NULL;
 	z->dir = e->dir;
 
 	return z;
diff --git a/src/stb_image.h b/src/stb_image.h
index 3999e1665..99115a67b 100644
--- a/src/stb_image.h
+++ b/src/stb_image.h
@@ -3389,8 +3389,8 @@ static int stbi__free_jpeg_components(stbi__jpeg *z, int ncomp, int why)
       }
       if (z->img_comp[i].raw_coeff) {
          STBI_FREE(z->img_comp[i].raw_coeff);
-         z->img_comp[i].raw_coeff = 0;
-         z->img_comp[i].coeff = 0;
+         z->img_comp[i].raw_coeff = NULL;
+         z->img_comp[i].coeff = NULL;
       }
       if (z->img_comp[i].linebuf) {
          STBI_FREE(z->img_comp[i].linebuf);
@@ -3470,8 +3470,8 @@ static int stbi__process_frame_header(stbi__jpeg *z, int scan)
       // so these muls can't overflow with 32-bit ints (which we require)
       z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8;
       z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8;
-      z->img_comp[i].coeff = 0;
-      z->img_comp[i].raw_coeff = 0;
+      z->img_comp[i].coeff = NULL;
+      z->img_comp[i].raw_coeff = NULL;
       z->img_comp[i].linebuf = NULL;
       z->img_comp[i].raw_data = stbi__malloc_mad2(z->img_comp[i].w2, z->img_comp[i].h2, 15);
       if (z->img_comp[i].raw_data == NULL)