malloc return check in Save_GIF()
also translated comments from French to English
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Thomas Bernard
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6b6f8790d5
commit
6f21c7e753
103
src/giformat.c
103
src/giformat.c
@ -831,6 +831,14 @@ static byte GIF_next_pixel(T_IO_Context *context, T_GIF_context *gif, T_GIF_IDB
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return temp;
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}
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struct gif_alphabet {
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word prefix[4096]; // code prefix array
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word suffix[4096]; // code suffix array
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word daughter[4096]; // daughter strings array (greater length)
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word sister[4096]; // sister strings array (same length)
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word free; // first free slot in the alphabet
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word max; // maximum number of entry in the alphabet
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};
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/// Save a GIF file
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void Save_GIF(T_IO_Context * context)
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@ -838,12 +846,7 @@ void Save_GIF(T_IO_Context * context)
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FILE * GIF_file;
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byte GIF_buffer[256]; // buffer d'écriture de bloc de données compilées
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word * alphabet_prefix; // Table des préfixes des codes
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word * alphabet_suffix; // Table des suffixes des codes
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word * alphabet_daughter; // Table des chaînes filles (plus longues)
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word * alphabet_sister; // Table des chaînes soeurs (même longueur)
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word alphabet_free; // Position libre dans l'alphabet
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word alphabet_max; // Nombre d'entrées possibles dans l'alphabet
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struct gif_alphabet * alphabet;
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word start; // Code précédent (sert au linkage des chaînes)
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int descend; // Booléen "On vient de descendre"
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@ -873,10 +876,13 @@ void Save_GIF(T_IO_Context * context)
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// La signature du fichier a été correctement écrite.
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// Allocation de mémoire pour les tables
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alphabet_prefix = (word *)GFX2_malloc(4096*sizeof(word));
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alphabet_suffix = (word *)GFX2_malloc(4096*sizeof(word));
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alphabet_daughter = (word *)GFX2_malloc(4096*sizeof(word));
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alphabet_sister = (word *)GFX2_malloc(4096*sizeof(word));
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alphabet = (struct gif_alphabet *)GFX2_malloc(sizeof(struct gif_alphabet));
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if (alphabet == NULL)
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{
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File_error = 1;
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fclose(GIF_file);
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return;
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}
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// On initialise le LSDB du fichier
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if (Config.Screen_size_in_GIF && Screen_width >= context->Width && Screen_height >= context->Height)
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@ -1173,14 +1179,14 @@ void Save_GIF(T_IO_Context * context)
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GIF.stop=0;
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// Réintialisation de la table:
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alphabet_free=clear + 2; // 258 for 8bpp
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GIF.nb_bits =IDB.Nb_bits_pixel + 1; // 9 for 8 bpp
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alphabet_max =clear+clear-1; // 511 for 8bpp
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alphabet->free = clear + 2; // 258 for 8bpp
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GIF.nb_bits = IDB.Nb_bits_pixel + 1; // 9 for 8 bpp
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alphabet->max = clear+clear-1; // 511 for 8bpp
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GIF_set_code(GIF_file, &GIF, GIF_buffer, clear); //256 for 8bpp
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for (start=0;start<4096;start++)
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for (start=0; start<4096; start++)
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{
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alphabet_daughter[start] = GIF_INVALID_CODE;
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alphabet_sister[start] = GIF_INVALID_CODE;
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alphabet->daughter[start] = GIF_INVALID_CODE;
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alphabet->sister[start] = GIF_INVALID_CODE;
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}
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////////////////////////////////////////////// COMPRESSION LZW //
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@ -1194,12 +1200,12 @@ void Save_GIF(T_IO_Context * context)
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// look for (current_string,current_char) in the alphabet
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while ( (index != GIF_INVALID_CODE) &&
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( (current_string!=alphabet_prefix[index]) ||
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(current_char !=alphabet_suffix[index]) ) )
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( (current_string != alphabet->prefix[index]) ||
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(current_char != alphabet->suffix[index]) ) )
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{
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descend=0;
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start=index;
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index=alphabet_sister[index];
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descend = 0;
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start = index;
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index = alphabet->sister[index];
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}
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if (index != GIF_INVALID_CODE)
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@ -1208,9 +1214,9 @@ void Save_GIF(T_IO_Context * context)
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// We have found (current_string,current_char) in the alphabet
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// at the index position. So go on and prepare for then next character
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descend=1;
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start=current_string=index;
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index=alphabet_daughter[index];
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descend = 1;
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start = current_string = index;
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index = alphabet->daughter[index];
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}
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else
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{
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@ -1218,44 +1224,44 @@ void Save_GIF(T_IO_Context * context)
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// so write current_string to the Gif stream
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GIF_set_code(GIF_file, &GIF, GIF_buffer, current_string);
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if(alphabet_free < 4096) {
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if(alphabet->free < 4096) {
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// link current_string and the new one
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if (descend)
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alphabet_daughter[start]=alphabet_free;
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alphabet->daughter[start] = alphabet->free;
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else
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alphabet_sister[start]=alphabet_free;
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alphabet->sister[start] = alphabet->free;
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// add (current_string,current_char) to the alphabet
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alphabet_prefix[alphabet_free]=current_string;
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alphabet_suffix[alphabet_free]=current_char;
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alphabet_free++;
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alphabet->prefix[alphabet->free] = current_string;
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alphabet->suffix[alphabet->free] = current_char;
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alphabet->free++;
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}
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if (alphabet_free >= 4096)
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if (alphabet->free >= 4096)
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{
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// clear alphabet
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GIF_set_code(GIF_file, &GIF, GIF_buffer, clear); // 256 for 8bpp
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alphabet_free=clear+2; // 258 for 8bpp
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GIF.nb_bits =IDB.Nb_bits_pixel + 1; // 9 for 8bpp
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alphabet_max =clear+clear-1; // 511 for 8bpp
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alphabet->free=clear+2; // 258 for 8bpp
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GIF.nb_bits = IDB.Nb_bits_pixel + 1; // 9 for 8bpp
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alphabet->max = clear+clear-1; // 511 for 8bpp
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for (start=0;start<4096;start++)
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{
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alphabet_daughter[start] = GIF_INVALID_CODE;
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alphabet_sister[start] = GIF_INVALID_CODE;
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alphabet->daughter[start] = GIF_INVALID_CODE;
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alphabet->sister[start] = GIF_INVALID_CODE;
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}
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}
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else if (alphabet_free>alphabet_max+1)
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else if (alphabet->free > (alphabet->max + 1))
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{
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// On augmente le nb de bits
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GIF.nb_bits++;
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alphabet_max = (1<<GIF.nb_bits)-1;
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alphabet->max = (1<<GIF.nb_bits)-1;
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}
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// initialize current_string as the string "current_char"
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index=alphabet_daughter[current_char];
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start=current_string=current_char;
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descend=1;
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index = alphabet->daughter[current_char];
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start = current_string = current_char;
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descend = 1;
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}
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}
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@ -1264,18 +1270,18 @@ void Save_GIF(T_IO_Context * context)
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// Write the last code (before EOF)
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GIF_set_code(GIF_file, &GIF, GIF_buffer, current_string);
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// we need to update alphabet_free / GIF.nb_bits here because
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// we need to update alphabet->free / GIF.nb_bits here because
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// the decoder will update them after each code,
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// so in very rare cases there might be a problem if we
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// don't do it.
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// see http://pulkomandy.tk/projects/GrafX2/ticket/125
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if(alphabet_free < 4096)
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if(alphabet->free < 4096)
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{
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alphabet_free++;
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if ((alphabet_free > alphabet_max+1) && (GIF.nb_bits < 12))
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alphabet->free++;
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if ((alphabet->free > alphabet->max+1) && (GIF.nb_bits < 12))
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{
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GIF.nb_bits++;
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alphabet_max = (1 << GIF.nb_bits) - 1;
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alphabet->max = (1 << GIF.nb_bits) - 1;
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}
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}
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@ -1351,10 +1357,7 @@ void Save_GIF(T_IO_Context * context)
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File_error=1;
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// Libération de la mémoire utilisée par les tables
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free(alphabet_sister);
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free(alphabet_daughter);
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free(alphabet_suffix);
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free(alphabet_prefix);
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free(alphabet);
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} // On a pu écrire la signature du fichier
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else
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